WARRANT

“Fair Market Value” of a share of Preferred Stock (or fully paid and nonassessable shares of the Company’s common stock, $0.01 par value (the “Common Stock”) if the Preferred Stock has been automatically converted into Common Stock) as of the date that the net issue election is made (the “Determination Date”) shall mean:

(i) If the net issue election is made in connection with and contingent upon the closing of the sale of the Company’s Common Stock to the public in a public offering pursuant to a Registration Statement under the 1933 Act (a “Public Offering”), and if the Company’s Registration Statement relating to such Public Offering (“Registration Statement”) has been declared effective by the Securities and Exchange Commission, then the initial “Price to Public” specified in the final prospectus with respect to such offering multiplied by the number of shares of Common Stock into which each share of Preferred Stock is then convertible.

(ii) If the net issue election is not made in connection with and contingent upon a Public Offering, then as follows:

(a) If traded on a securities exchange or the Nasdaq National Market, the fair market value of the Common Stock shall be deemed to be the average of the closing or last reported sale prices of the Common Stock on such exchange or market over the five-trading-day period ending five trading days prior to the Determination Date, and the fair market value of the Preferred Stock shall be deemed to be such fair market value of the Common Stock multiplied by the number of shares of Common Stock into which each share of Preferred Stock is then convertible;

(b) If otherwise traded in an over-the-counter market, the fair market value of the Common Stock shall be deemed to be the average of the closing bid or sales prices, whichever is applicable, of the Common Stock over the five-trading-day period ending five trading days prior to the Determination Date, and the fair market value of the Preferred Stock shall be deemed to be such fair market value of the Common Stock multiplied by the number of shares of Common Stock into which each share of Preferred Stock is then convertible; and

(c) If there is no public market for the Common Stock, then fair market value shall be determined in good faith by the Company’s Board of Directors.

5. Partial Exercise. This Warrant may be exercised in part, and the Holder shall be entitled to receive a new warrant, which shall be dated as of the date of this Warrant, covering the number of shares in respect of which this Warrant shall not have been exercised.

6. Fractional Shares. In no event shall any fractional share of Preferred Stock be issued upon any exercise of this Warrant. If, upon exercise of this Warrant in its entirety, the Holder would, except as provided in this Section 6, be entitled to receive a fractional share of Preferred Stock, then the Company shall pay to the Holder an amount in cash equal to such fraction multiplied by the Purchase Price in effect under this Warrant.

7. Expiration Date; Automatic Exercise. This Warrant shall expire at the earliest to occur of (the “Expiration Date”) (i) at 5:00 p.m. (Mountain time) on July 20, 2016; (ii) three years after the closing of the initial Public Offering of the Company on the NASDAQ or other stock exchange in the United States, and shall be void thereafter.

Notwithstanding the term of this Warrant fixed pursuant to this Section 7, and provided Holder has received advance written notice of at least twenty (20) business days and this Warrant has not earlier expired or been exercised in full, and provided this Warrant has not been assumed by the successor entity (or parent thereof), immediately prior to the consummation of a Merger (as defined below), this Warrant shall automatically be exercised pursuant to Section 4 hereof, without any action by Holder. “Merger” means: (i) a sale of all or substantially all of the Company’s assets to an Unaffiliated Entity (as defined below), or (ii) the merger, consolidation or acquisition of the Company with, into or by an Unaffiliated Entity (other than a merger or consolidation for the principle purpose of changing the domicile of the Company

or a transaction or series of transactions principally for bona fide equity financing purposes), that results in the transfer of fifty percent (50%) or more of the outstanding voting power of the Company. “Unaffiliated Entity” means any entity that is owned or controlled by parties who own less than twenty percent (20%) of the combined voting power of the outstanding voting securities of the Company immediately prior to such merger, consolidation or acquisition. Notwithstanding the foregoing, in the event that any outstanding warrants to purchase equity securities of the Company are assumed by the successor entity of a Merger (or parent thereof), this Warrant shall also be similarly assumed. The Company agrees to promptly give the Holder written notice of any proposed Merger and written notice of termination of any proposed Merger. Notwithstanding anything to the contrary in this Warrant, the Holder may rescind any exercise of its purchase rights after a notice of termination of the proposed Merger if the exercise of this Warrant occurred after the Company notified the Holder that the Merger was proposed or if the exercise was otherwise precipitated by such proposed Merger, provided, however that such rescission right must be exercised within thirty (30) days of receipt of such written notice of termination of the proposed Merger. In the event of such rescission, this Warrant will continue to be exercisable on the same terms and conditions.

8. Reserved Shares; Valid Issuance. The Company covenants that it will at all times from and after the date hereof reserve and keep available such number of its authorized shares of Preferred Stock and Common Stock free from all preemptive or similar rights therein, as will be sufficient to permit, respectively, the exercise of this Warrant in full and the conversion into shares of Common Stock of all shares of Preferred Stock receivable upon such exercise. The Company further covenants that such shares as may be issued pursuant to such exercise and/or conversion will, upon issuance, be duly and validly issued, fully paid and nonassessable and free from all taxes, liens and charges with respect to the issuance thereof.

9. Stock Splits and Dividends. If after the date hereof the Company shall subdivide the Preferred Stock, by split-up or otherwise, or combine the Preferred Stock, or issue additional shares of Preferred Stock in payment of a stock dividend on the Preferred Stock, the number of shares of Preferred Stock issuable on the exercise of this Warrant shall forthwith be proportionately increased in the case of a subdivision or stock dividend, or proportionately decreased in the case of a combination, and the Purchase Price shall forthwith be proportionately decreased in the case of a subdivision or stock dividend, or proportionately increased in the case of a combination.

10. Adjustments for Diluting Issuances. The other antidilution rights applicable to the Preferred Stock and the Common Stock of the Company are set forth in the Amended and Restated Certificate of Incorporation, as amended from time to time (the “Articles”), a true and complete copy in its current form which is attached hereto as Exhibit A. Such rights shall not be restated, amended or modified in any manner which affects the Holder differently than the holders of Preferred Stock without such Holder’s prior written consent. The Company shall promptly provide the Holder hereof with any restatement, amendment or modification to the Articles promptly after the same has been made.

11. Mergers and Reclassifications. If after the date hereof the Company shall enter into any Reorganization (as hereinafter defined), then, as a condition of such Reorganization, lawful provisions shall be made, and duly executed documents evidencing the same from the Company or its successor shall be delivered to the Holder, so that the Holder shall thereafter have the right to purchase, at a total price not to exceed that payable upon the exercise of this Warrant in full, the kind and amount of shares of stock and other securities and property receivable upon such Reorganization by a holder of the number of shares of Preferred Stock which might have been purchased by the Holder upon the exercise of this Warrant immediately prior to such Reorganization, and in any such case appropriate provisions shall be made with respect to the rights and interest of the Holder to the end that the provisions hereof (including without limitation, provisions for the adjustment of the Purchase Price and the number of shares issuable hereunder and the provisions relating to the net issue election) shall thereafter be applicable in relation to any shares of stock or other securities and property thereafter deliverable upon exercise hereof. For the purposes of this Section 11, the term “Reorganization” shall include without limitation any reclassification, capital reorganization or change of the Preferred Stock (other than as a result of a subdivision, combination or stock dividend provided for in Section 9 hereof), or any consolidation of the Company with, or merger of the Company into, another corporation or other business organization (other than a Merger provided for in Section 7 hereof).

12. Certificate of Adjustment. Whenever the Purchase Price is adjusted, as herein provided, the Company shall promptly deliver to the Holder a certificate of the Company’s chief financial officer setting forth the Purchase Price after such adjustment and setting forth a brief statement of the facts requiring such adjustment.

13. Notices of Record Date, Etc. In the event of:

(a) any taking by the Company of a record of the holders of any class of securities for the purpose of determining the holders thereof who are entitled to receive any dividend or other distribution, or any right to subscribe for, purchase, sell or otherwise acquire or dispose of any shares of stock of any class or any other securities or property;

(b) any reclassification of the capital stock of the Company, capital reorganization of the Company, consolidation or merger of the Company with another entity, or sale or conveyance of all or substantially all of its assets; or

(c) any voluntary or involuntary dissolution, liquidation or winding-up of the Company; then in each such event the Company will provide or cause to be provided to the Holder a written notice thereof. Such notice shall be provided at least twenty (20) business days prior to the date specified in such notice on which any such action is to be taken.

14. Representations, Warranties and Covenants. This Warrant is issued and delivered by the Company and accepted by each Holder on the basis of the following representations, warranties and covenants made by the Company:

(a) The Company has all necessary corporate authority to issue, execute and deliver this Warrant and to perform its obligations hereunder. This Warrant has been duly authorized, issued, executed and delivered by the Company and is the valid and binding obligation of the Company, enforceable against the Company in accordance with its terms.

(b) The shares of Preferred Stock issuable upon the exercise of this Warrant have been duly authorized and reserved for issuance by the Company and, when issued in accordance with the terms hereof, will be validly issued, fully paid and nonassessable.

(c) Subject in part to the truth and accuracy of Holder’s representations and covenants set forth in Section 17, the issuance, execution and delivery of this Warrant do not, and the issuance of the shares of Preferred Stock upon the exercise of this Warrant in accordance with the terms hereof will not, (i) violate or contravene the Company’s Articles or by-laws, or any law, statute, regulation, rule, judgment or order applicable to the Company or (ii) violate, contravene or result in a breach or default under any contract, agreement or instrument to which the Company is a party or by which the Company or any of its assets are bound.

(d) Until the earlier of the expiration or exercise in full of this Warrant, the Company will provide to the Holder the financial and other information described in the Loan Agreement.

(e) So long as this Warrant has not terminated, Holder shall be entitled to receive such financial and other information as the Holder would be entitled to receive under the Stock Purchase Agreement applicable to the Preferred Stock if Holder were a holder of that number of shares issuable upon full exercise of this Warrant.

(f) As of the date hereof, the authorized capital stock of the Company consists of (i) 25,000,000 shares of Common Stock, of which 1,164,312 shares are issued and outstanding 13,922,337 shares are reserved for issuance upon conversion of the Preferred Stock, and up to 2,287,493 shares of which have been reserved for issuance under the Company’s 2006 Omnibus Securities and Incentive Plan; and (ii) 13,922,337 shares of Preferred Stock, consisting of 1,000,000 shares designated as Series A-1 Preferred Stock, all of which are issued and outstanding; 1,084,000 shares designated as Series A-2 Preferred Stock, all of which are issued and outstanding; 930,000 shares designated as Series A-3 Preferred Stock, of which 915,000 shares are issued and outstanding and 15,000 shares have been reserved for issuance upon the exercise of warrants; 873,390 shares designated as Series A-4 Preferred Stock, of which 858,369 shares are issued and outstanding and 15,021 shares have been reserved for issuance upon the exercise of a warrants; 1,027,397 shares designated as Series B Preferred Stock, all of which are issued and outstanding, 3,325,731 shares designated as Series C Preferred Stock, 3,102,190 of which are issued and outstanding, and up to 223,541 shares of which have been reserved for issuance upon the exercise of warrants, and 5,681,819 shares designated as Series D Preferred Stock, of which 3,480,116 shares are issued and outstanding and 55,000 shares have been reserved for issuance upon the exercise of this Warrant. Attached hereto as Exhibit B is a capitalization table summarizing the capitalization of the Company. From the date hereof

until the earlier of the expiration or exercise in full of this Warrant, once per calendar quarter, the Company will provide Holder with a current capitalization table indicating changes, if any, to the number of outstanding shares of common stock and preferred stock.

15. Registration Rights. The Company grants to the Holder all the rights of a “Holder” and an “Investor” under the Company’s Fourth Amended and Restated Investors’ Rights Agreement dated as of April 24, 2009 (the “Rights Agreement”), including, without limitation, the registration rights contained therein, and agrees, if necessary, to use its commercially reasonable efforts to amend the Rights Agreement so that (i) the shares of Common Stock issuable upon conversion of the shares of Preferred Stock issuable upon exercise of this Warrant shall be “Registrable Securities,” and (ii) the Holder shall be a “Holder” and an “Investor” for all purposes of such Rights Agreement.

16. Amendment. The terms of this Warrant may be amended, modified or waived only with the written consent of the Holder and the Company.

17. Representations and Covenants of the Holder. This Warrant has been entered into by the Company in reliance upon the following representations and covenants of the Holder, which by its execution hereof the Holder hereby confirms:

(a) Investment Purpose. The right to acquire Preferred Stock or the Preferred Stock issuable upon exercise of the Holder’s rights contained herein will be acquired for investment and not with a view to the sale or distribution of any part thereof, and the Holder has no present intention of selling or engaging in any public distribution of the same except pursuant to a registration or exemption.

(b) Accredited Investor. Holder is an “accredited investor” within the meaning of the Securities and Exchange Rule 501 of Regulation D, as presently in effect.

(c) Private Issue. The Holder understands (i) that the Preferred Stock issuable upon exercise of the Holder’s rights contained herein is not registered under the 1933 Act or qualified under applicable state securities laws on the ground that the issuance contemplated by this Warrant will be exempt from the registration and qualifications requirements thereof, and (ii) that the Company’s reliance on such exemption is predicated on the representations set forth in this Section 17.

(d) Financial Risk. The Holder has such knowledge and experience in financial and business matters as to be capable of evaluating the merits and risks of its investment and has the ability to bear the economic risks of its investment.

(e) Rule 144. The Holder acknowledges that this Warrant, the Preferred Stock issuable upon exercise of this Warrant and the Common Stock issuable upon conversion of such Preferred Stock must be held indefinitely unless they are subsequently registered under the 1933 Act or an exemption from such registration is available. The Holder has been advised or is aware of the provisions of Rule 144 promulgated under the 1933 Act.

(f) Access to Data. The Holder has had an opportunity to discuss the Company’s business, management and financial affairs with the Company’s management and has had the opportunity to inspect the Company’s facilities.

18. Notices, Transfers, Etc.

(a) Any notice or written communication required or permitted to be given to the Holder may be given by certified mail or delivered to the Holder at the address most recently provided by the Holder to the Company.

(b) Subject to compliance with applicable federal and state securities laws, this Warrant may be transferred by the Holder with respect to any or all of the shares purchasable hereunder. Upon surrender of this Warrant to the Company, together with the assignment notice annexed hereto duly executed, for transfer of this Warrant as an entirety by the Holder, the Company shall issue a new warrant of the same denomination to the assignee, subject to the restrictions on transfer set forth in this Section 18(b) and the representations and covenants contained in Section 17. Upon surrender of

this Warrant to the Company, together with the assignment hereof properly endorsed, by the Holder for transfer with respect to a portion of the shares of Preferred Stock purchasable hereunder, the Company shall issue a new warrant to the assignee, in such denomination as shall be requested by the Holder hereof, and shall issue to such Holder a new warrant covering the number of shares in respect of which this Warrant shall not have been transferred.

(c) Each certificate representing (i) the Preferred Stock issuable upon exercise of this Warrant, (ii) the shares of Common Stock issued upon conversion of such Preferred Stock or (iii) any other securities issued in respect to such Preferred Stock or Common Stock upon any stock split, stock dividend, recapitalization, merger, consolidation or similar event, shall (unless such securities have been registered under the 1933 Act or sold under Rule 144) be stamped or otherwise imprinted with a legend substantially in the following form (in addition to any legend required under applicable state securities laws):

THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE BEEN ACQUIRED FOR INVESTMENT AND NOT WITH A VIEW TO, OR IN CONNECTION WITH, THE SALE AND DISTRIBUTION THEREOF, AND HAVE NOT BEEN REGISTERED UNDER THE 1933 ACT OR ANY STATE SECURITIES LAWS. SUCH SECURITIES MAY NOT BE SOLD OR TRANSFERRED IN THE ABSENCE OF SUCH REGISTRATION OR AN OPINION OF COUNSEL IN A FORM REASONABLY ACCEPTABLE TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED DUE TO AN EXEMPTION THEREFROM UNDER SAID ACT AND ANY APPLICABLE STATE SECURITIES LAWS.

(d) In case this Warrant shall be mutilated, lost, stolen or destroyed, the Company shall issue a new warrant of like tenor and denomination and deliver the same (i) in exchange and substitution for and upon surrender and cancellation of any mutilated Warrant, or (ii) in lieu of any Warrant lost, stolen or destroyed, upon receipt of an affidavit of the Holder or other evidence reasonably satisfactory to the Company of the loss, theft or destruction of such Warrant

19. No Impairment. The Company will not, by amendment of its Articles or through any reclassification, capital reorganization, consolidation, merger, sale or conveyance of assets, dissolution, liquidation, issue or sale of securities or any other voluntary action, avoid or seek to avoid the observance of performance of any of the terms of this Warrant, but will at all times in good faith assist in the carrying out of all such terms and in the taking of all such action as may be necessary or appropriate in order to protect the rights of the Holder.

20. No Voting or Dividend Rights. Nothing contained in this Warrant shall be construed as conferring upon Holder hereof the right to vote or to consent as a stockholder in respect of meetings of stockholders for the election of directors of the Company or any other matters or any rights whatsoever as a stockholder of Company. No dividends or interest shall be payable or accrued in respect of this Warrant or the interest represented hereby or the shares purchasable hereunder until, and only to the extent that, this Warrant shall have been exercised.

21. Governing Law. The provisions and terms of this Warrant shall be governed by and construed in accordance with the internal laws of the State of California without giving effect to its principles regarding conflicts of laws.

22. Successors and Assigns. This Warrant shall be binding upon the Company’s successors and assigns and shall inure to the benefit of the Holder’s successors, legal representatives and permitted assigns.

23. Business Days. If the last or appointed day for the taking of any action required or the expiration of any rights granted herein shall be a Saturday or Sunday or a legal holiday in California, then such action may be taken or right may be exercised on the next succeeding day which is not a Saturday or Sunday or such a legal holiday.

24. Qualifying Public Offering. If the Company shall effect a firm commitment underwritten public offering of shares of Common Stock which results in the conversion of the Preferred Stock into Common Stock pursuant to the Company’s Articles in effect immediately prior to such offering, then, effective upon such conversion, this Warrant shall change from the right to purchase shares of Preferred Stock to the right to purchase shares of Common Stock, and the Holder shall thereupon have the right to purchase, at a total price equal to that payable upon the exercise of this Warrant in full, the number of shares of Common Stock which would have been receivable by the Holder upon the exercise of this Warrant for shares of Preferred Stock immediately prior to such conversion of such shares of Preferred Stock into shares of

Common Stock, and in such event appropriate provisions shall be made with respect to the rights and interest of the Holder to the end that the provisions hereof (including, without limitation, the provisions for the adjustment of the Purchase Price and of the number of shares purchasable upon exercise of this Warrant and the provisions relating to the net issue election) shall thereafter be applicable to any shares of Common Stock deliverable upon the exercise hereof.

25. Value. The Company and the Holder agree that the value of this Warrant on the date of grant is $100.