70,000,000 Shares FACEBOOK, INC. CLASS ACOMMON STOCK (PAR VALUE $0.000006 PER SHARE) UNDERWRITING AGREEMENT

EXHIBIT 1.1

70,000,000 Shares

FACEBOOK, INC.

CLASS A COMMON STOCK (PAR VALUE $0.000006 PER SHARE)

UNDERWRITING AGREEMENT

December 20, 2013

December 20, 2013

J.P. Morgan Securities LLC

Merrill Lynch, Pierce, Fenner & Smith

Incorporated

Morgan Stanley & Co. LLC

Barclays Capital Inc.

BNP Paribas Securities Corp.

Citigroup Global Markets Inc.

RBC Capital Markets, LLC

Credit Suisse Securities (USA) LLC

HSBC Securities (USA) Inc.

RBS Securities Inc.

Standard Chartered Securities (Hong Kong) Limited

Piper Jaffray & Co.

Allen & Company LLC

c/o J.P. Morgan Securities LLC

383 Madison Avenue

New York, New York 10179

Ladies and Gentlemen:

Facebook, Inc., a Delaware corporation (the “Company”), proposes to issue and sell to the several Underwriters named in Schedule II hereto (the “Underwriters”), and certain stockholders of the Company (the “Selling Stockholders”) named in Schedule I hereto severally and not jointly propose to sell to the several Underwriters, an aggregate of 70,000,000 shares of the Class A common stock, par value $0.000006 per share, of the Company (the “Shares”), of which 27,004,761 shares are to be issued and sold by the Company and 42,995,239 shares are to be sold by the Selling Stockholders, such Selling Stockholders selling the amount set forth opposite such Selling Stockholder’s name in Schedule I hereto). The shares of Class A common stock, par value $0.000006 per share, of the Company to be outstanding after giving effect to the sales contemplated hereby are hereinafter referred to as the “Common Stock.” The Company and the Selling Stockholders are hereinafter sometimes collectively referred to as the “Sellers.”

The Company has filed with the Securities and Exchange Commission (the “Commission”) an automatic registration statement on Form S-3 (file no. 333-192944), including a prospectus, relating to the Shares. The registration statement as amended to the date of this Agreement, including the information (if any) deemed to be part of the registration statement at the time of effectiveness

pursuant to Rule 430A or Rule 430B under the Securities Act of 1933, as amended (the “Securities Act”), is hereinafter referred to as the “Registration Statement”, and the related prospectus in the form first used to confirm sales of the Shares (or in the form first made available to the Underwriters by the Company to meet requests of purchasers pursuant to Rule 173 under the Securities Act) is hereinafter referred to as the “Prospectus,” and the term “preliminary prospectus” means any preliminary form of the Prospectus. For purposes of this Agreement, “free writing prospectus” has the meaning set forth in Rule 405 under the Securities Act, and “Time of Sale Prospectus” means the documents and pricing information set forth opposite the caption “Time of Sale Prospectus” in Schedule III hereto. As used herein, the terms “Registration Statement,” “preliminary prospectus,” “Time of Sale Prospectus” and “Prospectus” shall include the documents, if any, incorporated by reference therein as of the date hereof. The terms “supplement,” “amendment,” and “amend” as used herein with respect to the Registration Statement, the Time of Sale Prospectus, any preliminary prospectus or the Prospectus shall include all documents subsequently filed by the Company with the Commission pursuant to the Securities Exchange Act of 1934, as amended (the “Exchange Act”), that are deemed to be incorporated by reference therein.

1. Representations and Warranties of the Company. The Company represents and warrants to and agrees with each of the Underwriters that:

(a) The Registration Statement has become effective; no stop order suspending the effectiveness of the Registration Statement is in effect, and no proceedings for such purpose are pending before or, to the Company’s knowledge, threatened by the Commission. The Company is a well-known seasoned issuer (as defined in Rule 405 under the Securities Act) eligible to use the Registration Statement as an automatic shelf registration statement and the Company has not received notice that the Commission objects to the use of the Registration Statement as an automatic shelf registration statement.

(b) (i) Each document, if any, filed or to be filed pursuant to the Exchange Act and incorporated by reference in the Time of Sale Prospectus or the Prospectus complied or will comply when so filed in all material respects with the Exchange Act and the applicable rules and regulations of the Commission thereunder, (ii) the Registration Statement, when it became effective, did not contain and, as amended or supplemented, if applicable, will not, as of the date of such amendment or supplement, contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (iii) the Registration Statement and the Prospectus comply and, as amended or supplemented, if applicable, will, as of the date of such amendment or supplement, comply in all material respects with the Securities Act and the applicable rules and regulations of the Commission thereunder, (iv) the Time of Sale Prospectus does not, and at the time of each sale of the Shares in connection with the offering when the Prospectus is not yet

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available to prospective purchasers and at the Closing Date (as defined in Section 5), the Time of Sale Prospectus, as then amended or supplemented by the Company, if applicable, will not, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, and (v) the Prospectus does not contain and, as amended or supplemented, if applicable, will not, as of its date or as of the Closing Date, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, except that the representations and warranties set forth in this paragraph do not apply to statements or omissions in the Registration Statement, the Time of Sale Prospectus or the Prospectus based upon information relating to any Underwriter furnished to the Company in writing by such Underwriter through you expressly for use therein.

(c) At the time of initial filing of the Registration Statement and since then, the Company was not and is not an “ineligible issuer” in connection with the offering pursuant to Rules 164, 405 and 433 under the Securities Act. Any free writing prospectus that the Company is required to file pursuant to Rule 433(d) under the Securities Act has been, or will be, filed with the Commission in accordance with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. Each free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act or that was prepared by or on behalf of or used or referred to by the Company complies or will at the time of such filing comply in all material respects with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. Except for the free writing prospectuses, if any, identified in Schedule III hereto, and electronic road shows, if any, each furnished to you before first use, the Company has not prepared, used or referred to, and will not, without your prior consent, prepare, use or refer to, any free writing prospectus.

(d) The Company has been duly incorporated, is validly existing as a corporation in good standing under the laws of the State of Delaware, has the corporate power and authority to own or lease its property and to conduct its business as described in the Time of Sale Prospectus and is duly qualified to transact business and is in good standing (to the extent the concept of good standing is applicable in such jurisdiction) in each jurisdiction in which the conduct of its business or its ownership or leasing of property requires such qualification, except to the extent that the failure to be so qualified or be in good standing (to the extent the concept of good standing is applicable in such jurisdiction) would not reasonably be likely to have a material adverse effect on the Company and its subsidiaries, taken as a whole (a “material adverse effect”).

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(e) Each of Facebook Ireland Limited, Vitesse LLC and Facebook Payments Inc. has been duly organized, is validly existing in good standing (to the extent the concept of good standing is applicable in such jurisdiction) under the laws of the jurisdiction of its formation, has the corporate or other similar power and authority to own its property and to conduct its business as described in the Time of Sale Prospectus and is duly qualified to transact business and is in good standing (to the extent the concept of good standing is applicable in such jurisdiction) in each jurisdiction in which the conduct of its business or its ownership or leasing of property requires such qualification, except to the extent that the failure to be so qualified or be in good standing would not have a material adverse effect; all of the issued shares of capital stock of each such subsidiary of the Company have been duly and validly authorized and issued, are fully paid and non-assessable and are owned directly by the Company or a subsidiary of the Company, free and clear of all liens, encumbrances, equities or claims, except to the extent that such liens, encumbrances, equities or claims would not have a material adverse effect.

(f) This Agreement has been duly authorized, executed and delivered by the Company.

(g) As of the Closing Date, the authorized capital stock of the Company conforms as to legal matters in all material respects to the description thereof contained in each of the Time of Sale Prospectus and the Prospectus.

(h) The shares of Common Stock (including the Shares to be sold by the Selling Stockholders) outstanding prior to the issuance of the Shares to be sold by the Company have been duly authorized and are validly issued, fully paid and non-assessable. The shares of Class B common stock outstanding prior to the issuance of the Shares to be sold by the Company have been duly authorized and are validly issued, fully paid and non-assessable. The shares of Class B common stock to be outstanding upon the exercise of an option by the Selling Stockholder identified as a “Founder Selling Stockholder” on Schedule I (the Selling Stockholder not identified as a Founder Selling Stockholder, the “Non-Founder Selling Stockholder”) have been duly authorized and, when issued and delivered upon the exercise of an option upon completion of the offering of the Shares contemplated hereby, will be validly issued, fully paid and non-assessable, and the issuance of such shares will not be subject to any preemptive or similar rights.

(i) The Shares to be sold by the Company have been duly authorized and, when issued, delivered and paid for in accordance with the terms of this Agreement, will be validly issued, fully paid and non-assessable, and the issuance of such Shares will not be subject to any preemptive or similar rights. To the Company’s knowledge, there are no registration rights applicable to the registration of Shares on the Registration Statement except for such rights that have been complied with or validly waived in writing.

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(j) The execution and delivery by the Company of, and the performance by the Company of its obligations under, this Agreement will not contravene any provision of (i) applicable law, or (ii) the certificate of incorporation or bylaws of the Company, or (iii) any agreement or other instrument binding upon the Company or any of its subsidiaries that is material to the Company and its subsidiaries, taken as a whole, or (iv) any judgment, order or decree of any governmental body, agency or court having jurisdiction over the Company or any subsidiary except in the cases of clauses (i), (iii) and (iv), for such contraventions as would not reasonably be likely to have a material adverse effect or adversely affect the ability of the Company to perform its obligations under this Agreement, and no consent, approval, authorization or order of, or qualification with, any governmental body or agency is required for the performance by the Company of its obligations under this Agreement, except such as may have been previously obtained or may be required by the securities or Blue Sky laws of the various states or foreign jurisdictions in connection with the offer and sale of the Shares.

(k) There has not occurred any material adverse change, or any development involving a prospective material adverse change, in the condition, financial or otherwise, or in the earnings, business or operations of the Company and its subsidiaries, taken as a whole, from that set forth in the Time of Sale Prospectus.

(l) There are no legal or governmental proceedings pending or, to the Company’s knowledge, threatened to which the Company or any of its subsidiaries is a party or to which any of the properties of the Company or any of its subsidiaries is subject (i) other than proceedings accurately described in all material respects in the Time of Sale Prospectus and proceedings that would not reasonably be likely to have a material adverse effect or adversely affect the power or ability of the Company to perform its obligations under this Agreement or to consummate the transactions contemplated by the Time of Sale Prospectus or (ii) that are required to be described in the Registration Statement or the Prospectus and are not so described in all material respects; and there are no statutes, regulations, contracts or other documents that are required to be described in the Registration Statement or the Prospectus or to be filed as exhibits to the Registration Statement that are not described in all material respects or filed as required.

(m) Each preliminary prospectus filed as part of the Registration Statement as originally filed or as part of any amendment thereto, or filed pursuant to Rule 424 under the Securities Act, complied when so filed in all material respects with the Securities Act and the applicable rules and regulations of the Commission thereunder.

(n) The Company is not, and after giving effect to the offering and sale of the Shares and the application of the proceeds thereof as described in the Prospectus will not be, required to register as an “investment company” as such term is defined in the Investment Company Act of 1940, as amended.

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(o) The Company and its subsidiaries (i) are in compliance with any and all applicable foreign, federal, state and local laws and regulations relating to the protection of human health and safety, the environment or hazardous or toxic substances or wastes, pollutants or contaminants (“Environmental Laws”), (ii) have received all permits, licenses or other approvals required of them under applicable Environmental Laws to conduct their respective businesses and (iii) are in compliance with all terms and conditions of any such permit, license or approval, except where such noncompliance with Environmental Laws, failure to receive required permits, licenses or other approvals or failure to comply with the terms and conditions of such permits, licenses or approvals would not, singly or in the aggregate, reasonably be likely to have a material adverse effect.

(p) There are no costs or liabilities associated with Environmental Laws (including, without limitation, any capital or operating expenditures required for clean-up, closure of properties or compliance with Environmental Laws or any permit, license or approval, any related constraints on operating activities and any potential liabilities to third parties) which would, singly or in the aggregate, reasonably be likely to have a material adverse effect.

(q) To the Company’s knowledge, there are no contracts, agreements or understandings between the Company and any person granting such person the right to require the Company to file a registration statement under the Securities Act with respect to any securities of the Company or to require the Company to include such securities with the Shares registered pursuant to the Registration Statement, other than registration rights that have been or will be satisfied, waived or complied with.

(r) Neither the Company nor any of its subsidiaries nor any director, executive officer, nor, to the Company’s knowledge, any employee, agent or representative of the Company or of any of its subsidiaries or controlled affiliates, has taken any action in furtherance of an offer, payment, promise to pay, or authorization or approval of the payment or giving of money, property, gifts or anything else of value, directly or indirectly, to any “government official” (including any officer or employee of a government or government-owned or controlled entity or of a public international organization, or any person acting in an official capacity for or on behalf of any of the foregoing, or any political party or party official or candidate for political office) to corruptly influence official action or secure an improper advantage for the Company; and the Company and its subsidiaries have conducted their businesses in compliance in all material respects with applicable anti-corruption laws and have instituted and maintain policies and procedures designed to promote and achieve compliance with such laws in all material respects.

(s) The operations of the Company and its subsidiaries are conducted in material compliance with all applicable financial recordkeeping and reporting requirements, including those of the Bank Secrecy Act, as amended by Title III of the Uniting and Strengthening America by Providing Appropriate Tools Required

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to Intercept and Obstruct Terrorism Act of 2001 (USA PATRIOT Act), and the applicable anti-money laundering statutes of jurisdictions where the Company and its subsidiaries conduct business, the rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the “Anti-Money Laundering Laws”), and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company or any of its subsidiaries with respect to the Anti-Money Laundering Laws is pending or, to the knowledge of the Company, threatened.

(t) (i) Neither the Company nor any of its subsidiaries, nor any director or officer thereof, nor, to the Company’s knowledge, any employee, agent, controlled affiliate or representative of the Company or any of its subsidiaries, is an individual or entity (“Person”) that is, or is owned or controlled by a Person that is:

(A) the subject of any sanctions administered or enforced by the U.S. Department of Treasury’s Office of Foreign Assets Control (“OFAC”), the United Nations Security Council (“UNSC”), the European Union (“EU”), Her Majesty’s Treasury (“HMT”) (collectively, “Sanctions”), nor

(B) located, organized or resident in a country or territory that is the subject of Sanctions (including, without limitation, Cuba, Iran, Libya, North Korea, Sudan and Syria).

(ii) The Company will not, directly or indirectly, use the proceeds of the offering, or lend, contribute or otherwise make available such proceeds to any subsidiary, joint venture partner or other Person:

(A) to fund any business of or any transactions with any Person or in any country or territory that, at the time of such funding, is the subject of Sanctions; or

(B) in any other manner that will result in a violation of Sanctions by any Person (including any Person participating in the offering, whether as underwriter, advisor, investor or otherwise).

(u) Subsequent to the respective dates as of which information is given in each of the Registration Statement, the Time of Sale Prospectus and the Prospectus, (i) the Company and its subsidiaries have not incurred any material liability or obligation, direct or contingent, nor entered into any material transaction; (ii) the Company has not purchased any of its outstanding capital stock (except for acquisitions of capital stock by the Company pursuant to agreements that permit the Company to repurchase such shares upon the applicable party’s termination of service to the Company), nor declared, paid or otherwise made any dividend or distribution of any kind on its capital stock other

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than ordinary and customary dividends; and (iii) there has not been any material change in the capital stock, short-term debt or long-term debt of the Company and its subsidiaries, except in each case as described in each of the Registration Statement, the Time of Sale Prospectus and the Prospectus, respectively.

(v) The Company and its subsidiaries have good and marketable title in fee simple to all real property and good and marketable title to all personal property (other than intellectual property, which is described below) owned by them which is material to the business of the Company and its subsidiaries, taken as a whole, in each case free and clear of all liens, encumbrances and defects except such as are described in the Time of Sale Prospectus or such as do not materially affect the value of such property and do not materially interfere with the use made and proposed to be made of such property by the Company and its subsidiaries; and any real property and buildings held under lease by the Company and its subsidiaries are held by them under valid, subsisting and, to the Company’s knowledge, enforceable leases with such exceptions as are not material and do not interfere with the use made and proposed to be made of such property and buildings by the Company and its subsidiaries, in each case except as described in the Time of Sale Prospectus.

(w) Except as disclosed in the Time of Sale Prospectus, to the knowledge of the Company, the Company and its subsidiaries own or possess, or can acquire on commercially reasonable terms, all material patents, patent rights, licenses, inventions, copyrights, know how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures), trademarks, service marks and trade names currently employed by them in connection with the business now operated by them, except where the failure to own, possess or acquire any of the foregoing would not reasonably be likely to result in a material adverse effect; and neither the Company nor any of its subsidiaries has received any written notice of infringement of or conflict with asserted rights of others with respect to any of the foregoing which, singly or in the aggregate, would reasonably be likely to have a material adverse effect.

(x) No material labor dispute with the employees of the Company or any of its subsidiaries exists, except as described in the Time of Sale Prospectus, or, to the knowledge of the Company, is imminent.

(y) The Company and its subsidiaries taken as a whole are insured by insurers of recognized financial responsibility against such losses and risks and in such amounts as the Company believes are prudent and customary in the businesses in which they are engaged; and neither the Company nor any of its subsidiaries has any reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business at a cost that would not have a material adverse effect, except as described in the Time of Sale Prospectus.

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(z) The Company and its subsidiaries possess all certificates, authorizations and permits issued by the appropriate federal, state or foreign regulatory authorities necessary to conduct their respective businesses, except where the failure to possess such certificates, authorizations and permits would not reasonably be likely to have a material adverse effect, and neither the Company nor any of its subsidiaries has received any written notice of proceedings relating to the revocation or modification of any such certificate, authorization or permit which, singly or in the aggregate, would reasonably be likely to have a material adverse effect, except as described in the Time of Sale Prospectus.

(aa) The Company and its subsidiaries maintain a system of internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”) and to maintain asset accountability; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; (iv) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences; and (v) the interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement fairly presents the information called for in all material respects. Except as described in the Time of Sale Prospectus, since the end of the Company’s most recent audited fiscal year, there has been (i) no material weakness in the Company’s internal control over financial reporting (whether or not remediated) and (ii) no change in the Company’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting.

(bb) The Company and each of its subsidiaries have filed all federal, state, local and foreign tax returns required to be filed through the date of this Agreement or have requested extensions thereof (except where the failure to file would not, individually or in the aggregate, have a material adverse effect) and have paid all taxes required to be paid thereon (except for cases in which the failure to file or pay would not reasonably be likely to have a material adverse effect, or, except as currently being contested in good faith and for which reserves required by U.S. GAAP have been created in the financial statements of the Company), and no unpaid tax deficiency has been determined adversely to the Company or any of its subsidiaries which has had (nor does the Company nor any of its subsidiaries have any notice or knowledge of any unpaid tax deficiency which could reasonably be expected to be determined adversely to the Company or its subsidiaries and which would reasonably be expected to have) a material adverse effect.

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(cc) The interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement fairly presents the information called for in all material respects and has been prepared in accordance with the Commission’s rules and guidelines applicable thereto.

2. Representations and Warranties of the Selling Stockholders. Each Selling Stockholder severally and not jointly represents and warrants to and agrees with each of the Underwriters that:

(a) This Agreement has been duly authorized, executed and delivered by such Selling Stockholder.

(b) The execution and delivery by such Selling Stockholder of, and the performance by such Selling Stockholder of its obligations under, this Agreement will not contravene (i) any provision of applicable law, (ii) any agreement or other instrument binding upon such Selling Stockholder or (iii) any judgment, order or decree of any governmental body, agency or court having jurisdiction over such Selling Stockholder except for such contraventions as would not reasonably be expected to have a material adverse effect on the ability of such Selling Stockholder to perform its obligations hereunder, and no consent, approval, authorization or order of, or qualification with, any governmental body or agency is required for the performance by such Selling Stockholder of its obligations under this Agreement except such as have been obtained and made under the Securities Act and such as may be required under the Exchange Act or the rules and regulations thereunder by the securities or Blue Sky laws of the various states or foreign jurisdictions in connection with the offer and sale of the Shares.

(c) With respect to any Shares to be sold by such Selling Stockholder that are outstanding on the date hereof, such Selling Stockholder has, and with respect to such Shares to be sold by such Selling Stockholder upon the conversion of Class B common stock or the exercise of options, on the Closing Date will have, valid title to, or a valid “security entitlement” within the meaning of Section 8-501 of the New York Uniform Commercial Code (the “UCC”) in respect of, the Shares to be sold by such Selling Stockholder free and clear of all security interests, claims, liens, equities or other encumbrances and the legal right and power, and all authorization and approval required by law, to enter into this Agreement and to sell, transfer and deliver the Shares to be sold by such Selling Stockholder or a security entitlement in respect of such Shares.

(d) Upon payment for the Shares to be sold by such Selling Stockholder pursuant to this Agreement, delivery of such Shares, as directed by the Underwriters, to Cede & Co. (“Cede”) or such other nominee as may be designated by the Depository Trust Company (“DTC”), registration of such Shares in the name of Cede or such other nominee and the crediting of such Shares on the books of DTC to securities accounts of the Underwriters (assuming that neither DTC nor any such Underwriter has notice of any adverse claim (within the meaning of Section 8-105 of the UCC) to such Shares), (A) DTC shall

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be a “protected purchaser” of such Shares within the meaning of Section 8-303 of the UCC, (B) under Section 8-501 of the UCC, the Underwriters will acquire a valid security entitlement in respect of such Shares and (C) no action based on any “adverse claim”, within the meaning of Section 8-102 of the UCC, to such Shares may be asserted against the Underwriters with respect to such security entitlement; for purposes of this representation, such Selling Stockholder may assume that when such payment, delivery and crediting occur, (x) such Shares will have been registered in the name of Cede or another nominee designated by DTC, in each case on the Company’s share registry in accordance with its certificate of incorporation, bylaws and applicable law, (y) DTC will be registered as a “clearing corporation” within the meaning of Section 8-102 of the UCC and (z) appropriate entries to the accounts of the several Underwriters on the records of DTC will have been made pursuant to the UCC.

(e) (i) the Registration Statement, when it became effective, did not contain and, as amended or supplemented, if applicable, will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (ii) the Time of Sale Prospectus does not, and at the time of each sale of the Shares in connection with the offering when the Prospectus is not yet available to prospective purchasers and at the Closing Date (as defined in Section 5), the Time of Sale Prospectus, as then amended or supplemented by the Company, if applicable, will not, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, and (iii) the Prospectus does not contain and, as amended or supplemented, if applicable, will not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the representations and warranties set forth in this paragraph 2(e) are limited to statements or omissions made in reliance upon information relating to such Selling Stockholder furnished to the Company in writing by such Selling Stockholder expressly for use in the Registration Statement, the Time of Sale Prospectus, the Prospectus or any amendments or supplements thereto, it being understood and agreed that the only information furnished by such Selling Stockholder consists of the name of such Selling Stockholder, the number of offered shares and the address and other information with respect to such Selling Stockholder (excluding percentages) which appear in the Time of Sale Prospectus in the table (and corresponding footnotes) under the caption “Selling Stockholders.”

3. Agreements to Sell and Purchase. Each Seller, severally and not jointly, hereby agrees to sell to the several Underwriters, and each Underwriter, upon the basis of the representations and warranties herein contained, but subject to the conditions hereinafter stated, agrees, severally and not jointly, to purchase from such Seller at $54.7748 a share (the “Purchase Price”) the number of Shares (subject to such adjustments to eliminate fractional shares as you may determine) that bears the same proportion to the number of Shares to be sold by such Seller as the number of Shares set forth in Schedule II hereto opposite the name of such Underwriter bears to the total number of Shares.

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4. Terms of Public Offering. The Sellers are advised by you that the Underwriters propose to make a public offering of their respective portions of the Shares as soon after the Registration Statement and this Agreement have become effective as in your judgment is advisable. The Sellers are further advised by you that the Shares are to be offered to the public initially at $55.05 a share (the “Public Offering Price”).

5. Payment and Delivery. Payment for the Shares to be sold by each Seller shall be made to such Seller in Federal or other funds immediately available in New York City against delivery of such Shares for the respective accounts of the several Underwriters at approximately 8:00 a.m., New York City time, on December 26, 2013. The time and date of such payment are hereinafter referred to as the “Closing Date.”

The Shares shall be registered in such names and in such denominations as you shall request in writing not later than one full business day prior to the Closing Date. The Shares shall be delivered to you on the Closing Date for the respective accounts of the several Underwriters. The Purchase Price payable by the Underwriters shall be (i) reduced by any transfer taxes paid by, or on behalf of, the Underwriters in connection with the transfer of the Shares to the Underwriters duly paid and (ii) subject to any withholding required by law.

6. Conditions to the Underwriters’ Obligations. The obligations of the Sellers to sell the Shares to the Underwriters and the several obligations of the Underwriters to purchase and pay for the Shares on the Closing Date are subject to the following conditions:

(a) Subsequent to the execution and delivery of this Agreement and prior to the Closing Date:

(i) there shall not have occurred any downgrading, nor shall any notice have been given of any intended or potential downgrading or of any review for a possible change that does not indicate the direction of the possible change, in the rating accorded any of the securities of the Company or any of its subsidiaries by any “nationally recognized statistical rating organization,” as such term is defined in Section 3(a)(62) of the Exchange Act; and

(ii) there shall not have occurred any change, or any development involving a prospective change, in the condition, financial or otherwise, or in the earnings, business or operations of the Company and its subsidiaries, taken as a whole, from that set forth in the Time of Sale Prospectus that, in your judgment, is material and adverse and that makes it, in your judgment, impracticable to market the Shares on the terms and in the manner contemplated in the Time of Sale Prospectus.

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(b) The Underwriters shall have received on the Closing Date a certificate, dated the Closing Date and signed on behalf of the Company by an executive officer of the Company, to the effect set forth in Section 6(a)(i) above and to the effect that the representations and warranties of the Company contained in this Agreement are true and correct as of the Closing Date and that the Company has complied with all of the agreements and satisfied all of the conditions on its part to be performed or satisfied hereunder on or before the Closing Date.

The officer signing and delivering such certificate may rely upon his or her knowledge as to proceedings threatened.

(c) The Underwriters shall have received on the Closing Date an opinion of Fenwick & West, LLP, outside counsel for the Company, dated the Closing Date, in the form acceptable to the Representative.

(d) The Underwriters shall have received on the Closing Date an opinion of (i) Kaye Scholer LLP, counsel for the Founder Selling Stockholder, and (ii) Arnold & Porter LLP, counsel for the Non-Founder Selling Stockholder, each dated the Closing Date and in the form acceptable to the Representative.

(e) The Underwriters shall have received on the Closing Date an opinion of Simpson Thacher & Bartlett LLP, counsel for the Underwriters, dated the Closing Date, in form and substance satisfactory to you.

With respect to Section 6(c) and Section 6(e) above, Fenwick & West LLP and Simpson Thacher & Bartlett LLP may state that their beliefs are based upon their participation in the preparation of the Registration Statement, the Time of Sale Prospectus and the Prospectus and any amendments or supplements thereto and review and discussion of the contents thereof, but are without independent check or verification, except as specified. With respect to Section 6(d) above, any counsel for the Selling Stockholders may rely upon the representations of each Selling Stockholder contained herein.

The opinions of Fenwick & West LLP and the counsel for the Selling Stockholders described in Sections 6(c) and 6(d) above shall be rendered to the Underwriters at the request of the Company or one or more of the Selling Stockholders, as the case may be, and shall so state therein.

(f) The Underwriters shall have received, on each of the date hereof and the Closing Date, a letter dated the date hereof or the Closing Date, as the case may be, in form and substance satisfactory to the Underwriters, from Ernst & Young, LLP, registered public accounting firm, containing statements and information of the type ordinarily included in accountants’ “comfort letters” to

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underwriters with respect to the financial statements and certain financial information contained in the Registration Statement, the Time of Sale Prospectus and the Prospectus; provided that the letter delivered on the Closing Date shall use a “cut-off date” not earlier than the date hereof.

(g) The chief financial officer of the Company shall have delivered to the Underwriters on the date hereof a certificate in a form reasonably acceptable to the Representative.

7. Covenants of the Company. The Company covenants with each Underwriter as follows:

(a) To furnish to you, without charge, five signed copies of the Registration Statement (including exhibits thereto and including documents incorporated by reference) and for delivery to each other Underwriter a conformed copy of the Registration Statement (without exhibits thereto but including documents incorporated by reference) and to furnish to you in New York City, without charge, prior to 10:00 a.m. New York City time on the business day next succeeding the date of this Agreement and during the period mentioned in Section 7(e) or 7(f) below, as many copies of the Time of Sale Prospectus, the Prospectus, any documents incorporated therein by reference and any supplements and amendments thereto or to the Registration Statement as you may reasonably request.

(b) Before amending or supplementing the Registration Statement, the Time of Sale Prospectus or the Prospectus, to furnish to you a copy of each such proposed amendment or supplement and not to file any such proposed amendment or supplement to which you reasonably object, and to file with the Commission within the applicable period specified in Rule 424(b) under the Securities Act any prospectus required to be filed pursuant to such Rule.

(c) To furnish to you a copy of each proposed free writing prospectus to be prepared by or on behalf of, used by, or referred to by the Company and not to use or refer to any proposed free writing prospectus to which you reasonably object.

(d) Not to take any action that would result in an Underwriter or the Company being required to file with the Commission pursuant to Rule 433(d) under the Securities Act a free writing prospectus prepared by or on behalf of the Underwriter that the Underwriter otherwise would not have been required to file thereunder.

(e) If the Time of Sale Prospectus is being used to solicit offers to buy the Shares at a time when the Prospectus is not yet available to prospective purchasers and any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Time of Sale Prospectus in order to make the statements therein, in the light of the circumstances, not misleading, or if any

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event shall occur or condition exist as a result of which the Time of Sale Prospectus conflicts with the information contained in the Registration Statement then on file, or if, in the reasonable opinion of counsel for the Underwriters, it is necessary to amend or supplement the Time of Sale Prospectus to comply with applicable law, forthwith to prepare, file with the Commission and furnish, at its own expense, to the Underwriters and to any dealer upon request, either amendments or supplements to the Time of Sale Prospectus so that the statements in the Time of Sale Prospectus as so amended or supplemented will not, in the light of the circumstances when the Time of Sale Prospectus is delivered to a prospective purchaser, be misleading or so that the Time of Sale Prospectus, as amended or supplemented, will no longer conflict with the Registration Statement, or so that the Time of Sale Prospectus, as amended or supplemented, will comply with applicable law.

(f) If, during such period after the first date of the public offering of the Shares as in the reasonable opinion of counsel for the Underwriters the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) of the Securities Act) is required by law to be delivered in connection with sales by an Underwriter or dealer, any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Prospectus in order to make the statements therein, in the light of the circumstances when the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) of the Securities Act) is delivered to a purchaser, not misleading, or if, in the reasonable opinion of counsel for the Underwriters, it is necessary to amend or supplement the Prospectus to comply with applicable law, forthwith to prepare, file with the Commission and furnish, at its own expense, to the Underwriters and to the dealers (whose names and addresses you will furnish to the Company) to which Shares may have been sold by you on behalf of the Underwriters and to any other dealers upon request, either amendments or supplements to the Prospectus so that the statements in the Prospectus as so amended or supplemented will not, in the light of the circumstances when the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) of the Securities Act) is delivered to a purchaser, be misleading or so that the Prospectus, as amended or supplemented, will comply with applicable law.

(g) To endeavor to qualify the Shares for offer and sale under the securities or Blue Sky laws of such jurisdictions as you shall reasonably request, provided, however, that nothing contained herein shall require the Company to qualify to do business in any jurisdiction, to execute a general consent to service of process in any jurisdiction or to subject itself to taxation in any jurisdiction in which it is not otherwise subject.

(h) To make generally available to the Company’s security holders and to you as soon as practicable an earnings statement covering a period of at least twelve months beginning with the first fiscal quarter of the Company occurring after the date of this Agreement which shall satisfy the provisions of Section 11(a) of the Securities Act and the rules and regulations of the Commission thereunder.

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8. Covenants of the Sellers. Each Seller, severally and not jointly, covenants with each Underwriter to deliver to each Underwriter (or its agent), prior to or at the Closing Date, a properly completed and executed Internal Revenue Service (“IRS”) Form W-9 or an IRS Form W-8, as appropriate, together with all required attachments to such form.

9. Expenses. Whether or not the transactions contemplated in this Agreement are consummated or this Agreement is terminated, the Company agrees to pay or cause to be paid all expenses incident to the performance of their obligations under this Agreement, including: (i) the fees, disbursements and expenses of the Company’s counsel, and the Company’s accountants in connection with the registration and delivery of the Shares under the Securities Act and all other fees or expenses in connection with the preparation and filing of the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, the Prospectus, any free writing prospectus prepared by or on behalf of, used by, or referred to by the Company and amendments and supplements to any of the foregoing, including all printing costs associated therewith, and the mailing and delivering of copies thereof to the Underwriters and dealers, in the quantities hereinabove specified, (ii) all costs and expenses related to the transfer and delivery of the Shares to the Underwriters, including any transfer or other taxes payable thereon, (iii) all filing fees in connection with the qualification of the Shares for offer and sale under state securities laws as provided in Section 7(g) hereof, (iv) all filing fees in connection with the review and qualification of the offering of the Shares by the Financial Industry Regulatory Authority, (v) all costs and expenses incident to listing the Shares on the NASDAQ Global Select Market, (vi) the cost of printing certificates representing the Shares, (vii) the costs and charges of any transfer agent, registrar or depositary, and (viii) all other costs and expenses incident to the performance of the obligations of the Company hereunder for which provision is not otherwise made in this Section. It is understood, however, that except as provided in this Section 9, Section 11 entitled “Indemnity and Contribution” and the last paragraph of Section 13 below, the Underwriters will pay all of their costs and expenses, including fees and disbursements of their counsel, stock transfer taxes payable on resale of any of the Shares by them and any advertising expenses connected with any offers they may make.

The provisions of this Section 9 shall not supersede or otherwise affect any agreement that the Sellers may otherwise have for the allocation of such expenses among themselves.

10. Covenants of the Underwriters. Each Underwriter severally covenants with the Company not to take any action that would result in the Company being required to file with the Commission under Rule 433(d) a free writing prospectus prepared by or on behalf of such Underwriter that otherwise would not be required to be filed by the Company thereunder, but for the action of the Underwriter.

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11. Indemnity and Contribution. (a) The Company agrees to indemnify and hold harmless each Underwriter, each person, if any, who controls any Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act, and each affiliate of any Underwriter within the meaning of Rule 405 under the Securities Act from and against any and all losses, claims, damages and liabilities (including, without limitation, any legal or other expenses reasonably incurred in connection with defending or investigating any such action or claim) caused by any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or any amendment thereof, any preliminary prospectus, the Time of Sale Prospectus or any amendment or supplement thereto, any issuer free writing prospectus as defined in Rule 433(h) under the Securities Act, any Company information that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act, or the Prospectus or any amendment or supplement thereto, or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, except insofar as such losses, claims, damages or liabilities are caused by any such untrue statement or omission or alleged untrue statement or omission based upon information relating to any Underwriter furnished to the Company in writing by such Underwriter through you expressly for use therein.

(b) Each Selling Stockholder agrees, severally and not jointly, to indemnify and hold harmless (i) each Underwriter, each person, if any, who controls any Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act, and each affiliate of any Underwriter within the meaning of Rule 405 under the Securities Act, and (ii) the Company, its directors, its officers who sign the Registration Statement and each person, if any, who controls the Company within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act, from and against any and all losses, claims, damages and liabilities (including, without limitation, any legal or other expenses reasonably incurred in connection with defending or investigating any such action or claim) caused by any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or any amendment thereof, any preliminary prospectus, the Time of Sale Prospectus or any amendment or supplement thereto, any issuer free writing prospectus as defined in Rule 433(h) under the Securities Act, any Company information that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act, or the Prospectus or any amendment or supplement thereto, or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, but only with reference to information relating to such Selling Stockholder furnished in writing by or on behalf of such Selling Stockholder expressly for use in the Registration Statement, any preliminary prospectus, the

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Time of Sale Prospectus, any issuer free writing prospectus or the Prospectus or any amendment or supplement thereto, it being understood and agreed that the only information furnished by such Selling Stockholder consists of the name of such Selling Stockholder, the number of offered shares and the address and other information with respect to such Selling Stockholder (excluding percentages) which appear in the table (and corresponding footnotes) under the caption “Selling Stockholders” in the Time of Sale Prospectus. The liability of each Selling Stockholder under the indemnity agreement contained in this paragraph shall be limited to an amount equal to the aggregate Public Offering Price, less underwriting discounts and commissions, of the Shares sold by such Selling Stockholder under this Agreement.

(c) Each Underwriter agrees, severally and not jointly, to indemnify and hold harmless the Company, the Selling Stockholders, the directors of the Company, the officers of the Company who sign the Registration Statement and each person, if any, who controls the Company or any Selling Stockholder within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act from and against any and all losses, claims, damages and liabilities (including, without limitation, any legal or other expenses reasonably incurred in connection with defending or investigating any such action or claim) caused by any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or any amendment thereof, any preliminary prospectus, the Time of Sale Prospectus or any amendment or supplement thereto, any issuer free writing prospectus as defined in Rule 433(h) under the Securities Act, any Company information that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act or the Prospectus or any amendment supplement thereto, or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, but only with reference to information relating to such Underwriter furnished to the Company in writing by such Underwriter through you expressly for use in the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, any issuer free writing prospectus, or the Prospectus or any amendment or supplement thereto.

(d) In case any proceeding (including any governmental investigation) shall be instituted involving any person in respect of which indemnity may be sought pursuant to Section 11(a), 11(b)or 11(c), such person (the “indemnified party”) shall promptly notify the person against whom such indemnity may be sought (the “indemnifying party”) in writing and the indemnifying party, upon request of the indemnified party, shall retain counsel reasonably satisfactory to the indemnified party to represent the indemnified party and any others the indemnifying party may designate in such proceeding and shall pay the fees and disbursements of such counsel related to such proceeding. In any such proceeding, any indemnified party shall have the right to retain its own counsel, but the fees and expenses of such counsel shall be at the expense of such indemnified party unless (i) the indemnifying party and the indemnified party

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shall have mutually agreed in writing to the retention of such counsel or (ii) the named parties to any such proceeding (including any impleaded parties) include both the indemnifying party and the indemnified party and representation of both parties by the same counsel would be inappropriate due to actual or potential conflict of interests between them. It is understood that the indemnifying party shall not, in respect of the legal expenses of any indemnified party in connection with any proceeding or related proceedings in the same jurisdiction, be liable for (i) the fees and expenses of more than one separate firm (in addition to any local counsel) for all Underwriters and all persons, if any, who control any Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act or who are affiliates of any Underwriter within the meaning of Rule 405 under the Securities Act, (ii) the fees and expenses of more than one separate firm (in addition to any local counsel) for the Company, its directors, its officers who sign the Registration Statement and each person, if any, who controls the Company within the meaning of either such Section and (iii) the fees and expenses of more than one separate firm (in addition to any local counsel) for each Selling Stockholder and all persons, if any, who control such Selling Stockholder within the meaning of either such Section, and that all such fees and expenses shall be reimbursed as they are incurred. In the case of any such separate firm for the Underwriters and such control persons and affiliates of any Underwriters, such firm shall be designated in writing by J.P. Morgan Securities LLC. In the case of any such separate firm for the Company, and such directors, officers and control persons of the Company, such firm shall be designated in writing by the Company. In the case of any such separate firm for the Selling Stockholders and such control persons of any Selling Stockholders, such firm shall be designated in writing by the Non-Founder Selling Stockholder, with respect to the Non-Founder Selling Stockholder, and the Founder Selling Stockholder, with respect to the Founder Selling Stockholder. The indemnifying party shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the indemnifying party agrees to indemnify the indemnified party from and against any loss or liability by reason of such settlement or judgment. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement of any pending or threatened proceeding in respect of which any indemnified party is or could have been a party and indemnity could have been sought hereunder by such indemnified party, unless such settlement includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such proceeding and does not include a statement as to or an admission of fault, culpability or a failure to act by or on behalf of any indemnified party.

(e) To the extent the indemnification provided for in Section 11(a), 11(b) or 11(c) is unavailable to an indemnified party or insufficient in respect of any losses, claims, damages or liabilities referred to therein, then each indemnifying party under such paragraph, in lieu of indemnifying such indemnified party thereunder, shall contribute to the amount paid or payable by

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such indemnified party as a result of such losses, claims, damages or liabilities (i) in such proportion as is appropriate to reflect the relative benefits received by the indemnifying party or parties on the one hand and the indemnified party or parties on the other hand from the offering of the Shares or (ii) if the allocation provided by clause 11(e)(i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause 11(e)(i) above but also the relative fault of the indemnifying party or parties on the one hand and of the indemnified party or parties on the other hand in connection with the statements or omissions that resulted in such losses, claims, damages or liabilities, as well as any other relevant equitable considerations. The relative benefits received by the Sellers on the one hand and the Underwriters on the other hand in connection with the offering of the Shares shall be deemed to be in the same respective proportions as the net proceeds from the offering of the Shares (before deducting expenses) received by each Seller and the total underwriting discounts and commissions received by the Underwriters, in each case as set forth in the table on the cover of the Prospectus, bear to the aggregate Public Offering Price of the Shares. The relative fault of the Sellers on the one hand and the Underwriters on the other hand shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Sellers or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The Underwriters’ respective obligations to contribute pursuant to this Section 11 are several in proportion to the respective number of Shares they have purchased hereunder, and not joint.

(f) The Sellers and the Underwriters agree that it would not be just or equitable if contribution pursuant to this Section 11 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation that does not take account of the equitable considerations referred to in Section 11(e). The amount paid or payable by an indemnified party as a result of the losses, claims, damages and liabilities referred to in Section 11(e) shall be deemed to include, subject to the limitations set forth above, any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any such action or claim. Notwithstanding the provisions of this Section 11, (i) no Underwriter shall be required to contribute any amount in excess of the amount by which the total price at which the Shares underwritten by it and distributed to the public were offered to the public exceeds the amount of any damages that such Underwriter has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission and (ii) no Selling Stockholder shall be required to contribute an amount in excess of the amount by which the aggregate Public Offering Price, less underwriting discounts and commissions, of Shares sold by such Selling Stockholder exceeds the amount of any damages that such Selling Stockholder has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No person guilty of

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fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The remedies provided for in this Section 11 are not exclusive and shall not limit any rights or remedies which may otherwise be available to any indemnified party at law or in equity.

(g) The indemnity and contribution provisions contained in this Section 11 and the representations, warranties and other statements of the Company and the Selling Stockholders contained in this Agreement shall remain operative and in full force and effect regardless of (i) any termination of this Agreement, (ii) any investigation made by or on behalf of any Underwriter, any person controlling any Underwriter or any affiliate of any Underwriter, any Selling Stockholder or any person controlling any Selling Stockholder, or the Company, its officers or directors or any person controlling the Company and (iii) acceptance of and payment for any of the Shares.

12. Termination. The Underwriters may terminate this Agreement by notice given by you to the Company, if after the execution and delivery of this Agreement and prior to the Closing Date (i) trading generally shall have been suspended or materially limited on, or by, as the case may be, either of the New York Stock Exchange or the NASDAQ Global Select Market, (ii) trading of any securities of the Company shall have been suspended on any exchange or in any over-the-counter market, (iii) a material disruption in securities settlement, payment or clearance services in the United States shall have occurred, (iv) any moratorium on commercial banking activities shall have been declared by Federal or New York State authorities or (v) there shall have occurred any outbreak or escalation of hostilities, or any change in financial markets or any calamity or crisis that, in your judgment, is material and adverse and which, singly or together with any other event specified in this clause (v), makes it, in your judgment, impracticable or inadvisable to proceed with the offer, sale or delivery of the Shares on the terms and in the manner contemplated in the Time of Sale Prospectus or the Prospectus.

13. Effectiveness; Defaulting Underwriters. This Agreement shall become effective upon the execution and delivery hereof by the parties hereto.

If, on the Closing Date any one or more of the Underwriters shall fail or refuse to purchase Shares that it has or they have agreed to purchase hereunder on such date, and the aggregate number of Shares which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase is not more than one-tenth of the aggregate number of the Shares to be purchased on such date, the other Underwriters shall be obligated severally in the proportions that the number of Shares set forth opposite their respective names in Schedule II bears to the aggregate number of Shares set forth opposite the names of all such non-defaulting Underwriters, or in such other proportions as you may specify, to purchase the Shares which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase on such date; provided that in no event shall the

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number of Shares that any Underwriter has agreed to purchase pursuant to this Agreement be increased pursuant to this Section 13 by an amount in excess of one-ninth of such number of Shares without the written consent of such Underwriter. If, on the Closing Date, any Underwriter or Underwriters shall fail or refuse to purchase Shares and the aggregate number of Shares with respect to which such default occurs is more than one-tenth of the aggregate number of Shares to be purchased on such date, and arrangements satisfactory to you, the Company, and the Selling Stockholders for the purchase of such Shares are not made within 36 hours after such default, this Agreement shall terminate without liability on the part of any non-defaulting Underwriter, the Company or the Selling Stockholders. In any such case either you or the relevant Sellers shall have the right to postpone the Closing Date, but in no event for longer than seven days, in order that the required changes, if any, in the Registration Statement, in the Time of Sale Prospectus, in the Prospectus or in any other documents or arrangements may be effected. Any action taken under this paragraph shall not relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

If this Agreement shall be terminated by the Underwriters, or any of them, because of any failure or refusal on the part of any Seller to comply with the terms or to fulfill any of the conditions of this Agreement, or if for any reason any Seller shall be unable to perform its obligations under this Agreement (other than for failure or non-performance by a Seller due to the events described in Section 12 resulting from circumstances not specifically related to such Seller), any such Seller will reimburse the Underwriters or such Underwriters as have so terminated this Agreement with respect to themselves, severally, for all out-of-pocket expenses (including the fees and disbursements of their counsel) reasonably incurred by such Underwriters in connection with this Agreement or the offering contemplated hereunder.

14. Entire Agreement. (a) This Agreement, together with any contemporaneous written agreements and any prior written agreements (to the extent not superseded by this Agreement) that relate to the offering of the Shares, represents the entire agreement between the Company and the Selling Stockholders, on the one hand, and the Underwriters, on the other, with respect to the preparation of any preliminary prospectus, the Time of Sale Prospectus, the Prospectus, the conduct of the offering, and the purchase and sale of the Shares.

(b) The Company acknowledges that in connection with the offering of the Shares: (i) the Underwriters have acted at arm’s length, are not agents of, and owe no fiduciary duties to, the Company or any other person, (ii) the Underwriters owe the Company only those duties and obligations set forth in this Agreement and prior written agreements (to the extent not superseded by this Agreement), if any, and (iii) the Underwriters may have interests that differ from those of the Company. The Company waives to the full extent permitted by applicable law any claims it may have against the Underwriters arising from an alleged breach of fiduciary duty in connection with the offering of the Shares.

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15. Counterparts. This Agreement may be signed in two or more counterparts, each of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument.

16. Applicable Law. This Agreement shall be governed by and construed in accordance with the internal laws of the State of New York.

17. Headings. The headings of the sections of this Agreement have been inserted for convenience of reference only and shall not be deemed a part of this Agreement.

18. Notices. All communications hereunder shall be in writing and effective only upon receipt and if to the Underwriters shall be delivered, mailed or sent to you in care of J.P. Morgan Securities LLC, 383 Madison Avenue, New York, New York 10179 (fax: (212)  ###-###-####); Attention: Equity Syndicate Desk; if to the Company shall be delivered, mailed or sent to 1601 Willow Road, Menlo Park, California 94025, Attention: Chief Financial Officer, with a copy to the General Counsel; if to the Non-Founder Selling Stockholder shall be delivered, mailed or sent to the Non-Founder Selling Stockholder at 2865 Sand Hill Road, Suite 101, Menlo Park, California 94025, with a copy to Arnold & Porter LLP, 3 Embarcadero Center, 10th Floor, San Francisco, California 94111, Attention: Kenneth Hausman; and if to the Founder Selling Stockholder shall be delivered, mailed or sent to the Founder Selling Stockholder at 1601 Willow Road, Menlo Park, California 94025, with a copy to Kaye Scholer LLP, Two Palo Alto Square, 3000 El Camino Real, Suite 400, Palo Alto, California ###-###-####, Attention: Diane Holt Frankle. In accordance with the requirements of the USA Patriot Act, the Underwriters are required to obtain, verify and record information that identifies their clients, including the Company, which information may include the name and address of their respective clients, as well as other information that will allow the Underwriters to properly identify their clients.

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[Signature Page to Underwriting Agreement]

[Signature Page to Underwriting Agreement]

[Signature Page to Underwriting Agreement]

[Signature Page to Underwriting Agreement]

SCHEDULE I

I-1

SCHEDULE II

II-1

SCHEDULE III

III-1