[Signature page follows]

Exhibit 10.1

EXECUTION COPY

     STOCKHOLDERS AGREEMENT dated as of August 12, 2010 (this “Agreement”), among INTERNATIONAL BUSINESS MACHINES CORPORATION, a New York corporation (“Parent”), and each of THE INDIVIDUALS AND OTHER PARTIES LISTED ON SCHEDULE A ATTACHED HERETO (each, a “Stockholder” and, collectively, the “Stockholders”).

          WHEREAS Parent, Amaroo Acquisition Corp., a Delaware corporation and a wholly owned subsidiary of Parent (“Sub”), and Unica Corporation, a Delaware corporation (the “Company”), have contemporaneously with the execution of this Agreement entered into an Agreement and Plan of Merger dated as of the date hereof (as the same may be amended or supplemented, the “Merger Agreement”; capitalized terms used but not defined herein shall have the meanings set forth in the Merger Agreement);

          WHEREAS each Stockholder is the record or beneficial owner of the number of shares of Company Common Stock set forth opposite such Stockholder’s name on Schedule A (such shares of capital stock of the Company, the “Original Shares”, and together with any New Shares (as defined below), the “Subject Shares”); and

          WHEREAS as a condition to their willingness to enter into the Merger Agreement, Parent and Sub have requested that the Stockholders enter into this Agreement.

          NOW, THEREFORE, in consideration of the foregoing and the representations, warranties, covenants and agreements set forth herein and in the Merger Agreement, each party hereto agrees as follows:

          SECTION 1. Representations and Warranties of Each Stockholder. Each Stockholder jointly and severally hereby represents and warrants to Parent as follows:

          (a) Organization; Authority; Execution and Delivery; Enforceability. If such Stockholder is not a natural person, (i) such Stockholder is duly organized, validly existing and in good standing under the laws of its jurisdiction of organization, (ii) the execution and delivery of this Agreement by such Stockholder, the consummation by such Stockholder of the transactions contemplated by this Agreement and the compliance by such Stockholder with the terms of this Agreement have been duly authorized by all necessary action on the part of such Stockholder and its governing body, members, stockholders and trustees, as applicable, and (iii) no other proceedings on the part of such Stockholder (or such Stockholder’s governing body, members, stockholders or trustees, as applicable) are necessary to authorize this Agreement, to consummate the transactions contemplated by this Agreement or to comply with the terms of this Agreement. Such Stockholder has all requisite corporate, company, partnership or other power and authority to execute and deliver this Agreement (and each Person executing this Agreement on behalf of such Stockholder that is not a natural person has full power, authority and capacity to execute and deliver this Agreement on behalf of such Stockholder and to thereby bind such Stockholder), to consummate the transactions contemplated by this Agreement and to comply with the terms of this Agreement. This Agreement has been duly executed and delivered by such Stockholder and, assuming due

authorization, execution and delivery by Parent, constitutes a valid and binding obligation of such Stockholder, enforceable against such Stockholder in accordance with its terms. If such Stockholder is married and the Subject Shares of such Stockholder constitute community property or if spousal or other approval is required for this Agreement to be legal, valid and binding, this Agreement has been duly authorized, executed and delivered by, and constitutes a valid and binding agreement of, such Stockholder’s spouse, enforceable against such spouse in accordance with its terms.

          (b) No Conflicts; Consents. The execution and delivery of this Agreement, the consummation of the transactions contemplated by this Agreement and the compliance by such Stockholder with the terms of this Agreement do not and will not conflict with, or result in any violation or breach of, or default (with or without notice or lapse of time, or both) under, or give rise to a right of, or result in termination, amendment, cancelation or acceleration of any obligation or to loss of a material benefit under, or result in the creation of any Lien in or upon any of the properties or assets of such Stockholder under, or give rise to any increased, additional, accelerated or guaranteed rights or entitlements under, (i) if such Stockholder is not a natural person, any provision of any certificate of incorporation, bylaws, or trust or other organizational document of such Stockholder, (ii) any Contract to or by which such Stockholder is a party or bound or to or by which any of the properties or assets of such Stockholder (including such Stockholder’s Subject Shares) is bound or subject or (iii) subject to the governmental filings and other matters referred to in the following sentence, any Law or Judgment, in each case, applicable to such Stockholder or to such Stockholder’s properties or assets (including such Stockholder’s Subject Shares) other than, in the case of clauses (ii) and (iii) of this paragraph, conflicts, violations, breaches, defaults, rights, losses, Liens or entitlements that individually or in the aggregate are not reasonably likely to (x) impair in any material respect the ability of such Stockholder to perform its obligations under this Agreement or (y) prevent or materially impede or delay the consummation of any of the transactions contemplated by this Agreement. No consent, approval, order or authorization of, or registration, declaration or filing with, any Governmental Entity or other Person (including with respect to natural persons, any spouse, and with respect to trusts, any co-trustee or beneficiary) (“Consent”) is required by or with respect to such Stockholder in connection with the execution and delivery of this Agreement by such Stockholder, the consummation by such Stockholder of the transactions contemplated by this Agreement or the compliance by such Stockholder with the terms of this Agreement, except for (1) filings under the HSR Act and any other applicable competition, merger control, antitrust or similar law or regulation, (2) filings with the SEC of such reports under the Exchange Act as may be required in connection with this Agreement and the transactions contemplated hereby and (3) those Consents which have already been obtained.

          (c) Ownership. Such Stockholder is the record and beneficial owner of the number of Original Shares set forth opposite such Stockholder’s name on Schedule A, and such Stockholder’s Original Shares constitute all of the shares of Company Common Stock held of record, beneficially owned or for which voting power or disposition power is held by such Stockholder. Such Stockholder has good and marketable title, free and clear of any Liens, to those Original Shares of which such Stockholder is the record owner. Such Stockholder does not own, of record or beneficially, (i) any shares of capital stock of the Company other than the Original Shares or (ii) any option, warrant, call or other right to acquire or receive capital stock or other equity or voting interests in the Company, other than those set forth opposite such

Stockholder’s name on Schedule B. Such Stockholder has the sole right to vote and Transfer such Stockholder’s Original Shares, and none of such Stockholder’s Original Shares are subject to any voting trust or other agreement, arrangement or restriction with respect to the voting or the Transfer of such Stockholder’s Original Shares, except as set forth in Sections 3 and 4 of this Agreement.

          (d) Information. None of the information relating to such Stockholder provided by or on behalf of such Stockholder for inclusion in the Proxy Statement or any filing required to be made with the SEC by the Company, Parent or Sub will, at the respective times such documents are filed with the SEC and at the respective times such documents are first published, sent or given to the Company’s stockholders, at the time of any amendment or supplement of any such document or at the time of the Stockholders Meeting, contain any untrue statement of material fact or omit to state any material fact required to be stated therein or necessary in order to make the statements therein, in light of the circumstances under which they are made, not misleading.

          SECTION 2. Representations and Warranties of Parent. Parent hereby represents and warrants to each Stockholder as follows: Parent has all requisite power and authority to execute and deliver this Agreement, to consummate the transactions contemplated by this Agreement and to comply with the terms of this Agreement. The execution and delivery of this Agreement by Parent, the consummation by Parent of the transactions contemplated by this Agreement and the compliance by Parent with the terms of this Agreement have been duly authorized by all necessary action on the part of Parent and no other corporate proceedings on the part of Parent are necessary to authorize this Agreement or to consummate the transactions contemplated by this Agreement. This Agreement has been duly executed and delivered by Parent and, assuming due authorization (in the case of each Stockholder that is not a natural person), execution and delivery by each Stockholder, constitutes a valid and binding obligation of Parent, enforceable against Parent in accordance with its terms. The execution and delivery of this Agreement do not, and the consummation of the transactions contemplated by this Agreement and compliance by Parent with the terms of this Agreement will not, conflict with, or result in any violation or breach of, or default (with or without notice or lapse of time, or both) under, or give rise to a right of, or result in termination, cancelation or acceleration of any obligation or to loss of a material benefit under, or result in the creation of any Lien upon any of the properties or assets of Parent under, or give rise to any increased, additional, accelerated or guaranteed rights or entitlements under, any provision of (i) the certificate of incorporation or bylaws of Parent, (ii) any Contract to or by which Parent is a party or bound or to or by which any of the properties or assets of Parent is subject or bound or (iii) subject to the governmental filings and other matters referred to in the following sentence, any Law or Judgment, in each case, applicable to Parent or its properties or assets other than, in the case of clauses (ii) and (iii), conflicts, violations, breaches, defaults, rights, losses, Liens or entitlements that individually or in the aggregate are not reasonably likely to (x) impair in any material respect the ability of Parent to perform its obligations under this Agreement or (y) prevent or materially impede or delay the consummation of any of the transactions contemplated by this Agreement. No Consent is required by or with respect to Parent in connection with the execution and delivery of this Agreement by Parent or the consummation by Parent of the transactions contemplated hereby, other than as contemplated by the Merger Agreement.

          SECTION 3. Covenants of Each Stockholder. Each Stockholder jointly and severally covenants and agrees as follows:

          (a) At any meeting of the stockholders of the Company called to vote upon the Merger Agreement, the Merger or any of the other transactions contemplated by the Merger Agreement, or at any postponement or adjournment thereof, or in any other circumstances upon which a vote, consent, adoption or other approval (including by written consent solicitation) with respect to the Merger Agreement, the Merger or any of the other transactions contemplated by the Merger Agreement is sought, such Stockholder shall (i) appear at such meeting or otherwise cause its Subject Shares to be counted as present thereat for purposes of calculating a quorum and (ii) vote (or cause to be voted) all of such Stockholder’s Subject Shares in favor of, and shall consent to (or cause to be consented to), the adoption of the Merger Agreement and the approval of the terms thereof and of the Merger and each of the other transactions contemplated by the Merger Agreement.

          (b) Prior to the date that is the later of (x) the date of the meeting of the stockholders of the Company called to vote upon the Merger Agreement and (y) six months from the date of this Agreement, at any meeting of the stockholders of the Company or at any postponement or adjournment thereof or in any other circumstances upon which a vote, consent, adoption or other approval (including by written consent solicitation) is sought, such Stockholder shall vote (or cause to be voted) all of such Stockholder’s Subject Shares against, and shall not (and shall not commit or agree to) consent to (or cause to be consented to), any of the following: (i) any Takeover Proposal or any Acquisition Agreement relating thereto or (ii) any amendment of the Company Certificate or the Company Bylaws (other than pursuant to or as contemplated by the Merger Agreement) or any other proposal, action, agreement or transaction which, in the case of this clause (ii), could reasonably be expected to (A) result in a breach of any covenant, agreement, obligation, representation or warranty of the Company contained in the Merger Agreement or of the Stockholders contained in this Agreement, (B) prevent, impede, interfere or be inconsistent with, delay, discourage or adversely affect the timely consummation of the Merger or the other transactions contemplated by the Merger Agreement or by this Agreement, (C) dilute in any material respect the benefits to Parent or Sub of the Merger and the other transactions contemplated by the Merger Agreement or by this Agreement or (D) change in any manner the voting rights of the Company Common Stock (the matters described in clauses (i) and (ii), collectively, the “Vote-Down Matters”).

          (c) Such Stockholder shall not, and shall not commit or agree to, (i) sell, transfer, pledge, exchange, assign, tender or otherwise dispose of (including by gift, merger or otherwise by operation of law) (collectively, “Transfer”), or consent to or permit any Transfer of, any Subject Shares (or any interest therein) or any rights to acquire any securities or equity interests of the Company, or enter into any Contract, option, call or other arrangement with respect to the Transfer (including any profit-sharing or other derivative arrangement) of any Subject Shares (or any interest therein) or any rights to acquire any securities or equity interests of the Company, to any Person other than pursuant to this Agreement or the Merger Agreement, unless prior to any such Transfer the transferee of such Stockholder’s Subject Shares is a party to this Agreement, enters into a stockholder agreement with Parent on terms substantially identical to the terms of this Agreement or agrees to become a party to this Agreement pursuant to a joinder agreement satisfactory to Parent, or (ii) enter into any voting arrangement, whether

by proxy, voting agreement or otherwise, with respect to any Subject Shares or rights to acquire any securities or equity interests of the Company, other than this Agreement. Each certificate or other instrument representing any Subject Shares shall bear a legend that such Subject Shares are subject to the provisions of this Agreement, including this Section 3(c); provided, however, that nothing contained herein shall restrict the ability of such Stockholder to exercise any Stock Options.

          (d) (i) Such Stockholder shall not commit or agree to take any action inconsistent with or challenging the transactions contemplated by, or the terms of, this Agreement or the Merger Agreement. Such Stockholder hereby waives any rights of appraisal, or rights to dissent from the Merger, that such Stockholder may have.

     (ii) Such Stockholder shall not, directly or indirectly, issue any press release with respect to the Merger Agreement, this Agreement, the Merger or any of the other transactions contemplated by the Merger Agreement or by this Agreement without the prior written consent of Parent, except as may be required by applicable Law or court process.

     (iii) Such Stockholder shall use commercially reasonable efforts to consult with Parent prior to making any public statement with respect to the Merger Agreement, this Agreement, the Merger or any of the other transactions contemplated by the Merger Agreement or by this Agreement.

          (e) Such Stockholder hereby agrees that, in the event (i) of any stock or extraordinary dividend or other distribution, stock split, reverse stock split, recapitalization, reclassification, reorganization, combination or other like change, of or affecting the Subject Shares or (ii) that such Stockholder purchases or otherwise acquires beneficial ownership of or an interest in, or acquires the right to vote or share in the voting of, any shares of capital stock of the Company, in each case after the execution of this Agreement (including by conversion, the exercise of Stock Options, the vesting of RSUs, operation of law or otherwise) (collectively, the “New Shares”), such Stockholder shall deliver promptly to Parent written notice of its acquisition or receipt of New Shares which notice shall state the number of New Shares so acquired or received. Such Stockholder agrees that any New Shares acquired or received by such Stockholder pursuant to clause (i) or (ii) of this paragraph shall be subject to the terms of this Agreement, including all covenants, agreements, obligations, representations and warranties set forth herein, and shall constitute Subject Shares to the same extent as if those New Shares were owned by such Stockholder on the date of this Agreement. Such Stockholder agrees that this Agreement and the obligations hereunder shall be binding upon any Person to which record or beneficial ownership of such Stockholder’s Subject Shares shall pass, whether by operation of Law or otherwise, including such Stockholder’s heirs, guardians, administrators or successors, and such Stockholder further agrees to take all actions necessary to effectuate the foregoing.

          SECTION 4. Grant of Irrevocable Proxy; Appointment of Proxy. (a) Each Stockholder hereby irrevocably grants to, and appoints, Parent and any other individual designated in writing by Parent, and each of them individually, such Stockholder’s proxy and attorney-in-fact (with full power of substitution and re-substitution), for and in the name, place

and stead of such Stockholder, to vote all of such Stockholder’s Subject Shares at any meeting of stockholders of the Company or any adjournment or postponement thereof, or grant a consent or approval in respect of such Stockholder’s Subject Shares, (i) in favor of the adoption of the Merger Agreement and the approval of the terms thereof and of the Merger and each of the other transactions contemplated by the Merger Agreement, (ii) against any Vote-Down Matter and (iii) otherwise in accordance with Section 3 of this Agreement. The proxy granted in this Section 4 shall expire upon the expiration of all rights of Parent and Sub under Section 3 of this Agreement.

          (b) Each Stockholder represents that any proxies heretofore given in respect of such Stockholder’s Subject Shares are not irrevocable, and that all such proxies are hereby revoked.

          (c) Each Stockholder hereby affirms that the irrevocable proxy set forth in this Section 4 is given in connection with the execution of the Merger Agreement, and that such irrevocable proxy is given to secure the performance of the duties of such Stockholder under this Agreement. Each Stockholder hereby further affirms that the irrevocable proxy is coupled with an interest and may under no circumstances be revoked. Each Stockholder hereby ratifies and confirms all that such irrevocable proxy may lawfully do or cause to be done by virtue hereof. Each such irrevocable proxy is executed and intended to be irrevocable in accordance with the provisions of Section 212(e) of the DGCL.

          SECTION 5. Further Assurances. Each Stockholder shall, from time to time, execute and deliver, or cause to be executed and delivered, such additional or further consents, documents and other instruments as Parent may request for the purpose of effectuating the matters covered by this Agreement, including the grant of the proxies set forth in Section 4 of this Agreement.

          SECTION 6. Assignment. Neither this Agreement nor any of the rights, interests or obligations hereunder shall be assigned, in whole or in part, by operation of Law or otherwise, by any of the parties hereto without the prior written consent of the other parties hereto, except that Parent may in its sole discretion assign, in whole or in one or more parts, any or all of its rights, interests or obligations under this Agreement to any direct or indirect wholly owned Subsidiary of Parent, but no such assignment shall relieve Parent of any of its obligations under this Agreement. Any purported assignment in violation of this Section 6 shall be void. Subject to the preceding sentences of this Section 6, this Agreement shall be binding upon, inure to the benefit of and be enforceable by, the parties hereto and their respective successors and assigns.

          SECTION 7. Termination. This Agreement shall terminate upon the earlier of (i) the Effective Time and (ii) the termination of the Merger Agreement in accordance with its terms, other than Sections 3(b), 4(a) and 8, which shall survive and instead shall expire upon the expiration of all rights of Parent and Sub thereunder.

          SECTION 8. General Provisions. (a) Amendments. This Agreement may not be amended except by an instrument in writing signed by each of the parties hereto.

          (b) Notices. All notices or other communications required or permitted to be given hereunder shall be in writing and shall be delivered by hand or sent by facsimile or sent, postage prepaid, by registered, certified or express mail or reputable overnight courier service and shall be deemed given when so delivered by hand or sent by facsimile, or if mailed, three days after mailing (one business day in the case of express mail or overnight courier service), to Parent in accordance with Section 8.02 of the Merger Agreement and to the Stockholders at their respective addresses set forth on Schedule A (or at such other address for a party as shall be specified by notice given in accordance with this Section 8(b)).

          (c) Interpretation. When a reference is made in this Agreement to a Section or a Schedule, such reference shall be to a Section of, or a Schedule to, this Agreement unless otherwise indicated. The headings contained in this Agreement are for reference purposes only and shall not affect in any way the meaning or interpretation of this Agreement. Whenever the words “include”, “includes” or “including” are used in this Agreement, they shall be deemed to be followed by the words “without limitation”. The words “hereof”, “hereto”, “hereby”, “herein” and “hereunder” and words of similar import when used in this Agreement shall refer to this Agreement as a whole and not to any particular provision of this Agreement. The words “date hereof” shall refer to the date of this Agreement. The term “or” is not exclusive. The word “extent” in the phrase “to the extent” shall mean the degree to which a subject or other thing extends, and such phrase shall not mean simply “if”. The definitions contained in this Agreement are applicable to the singular as well as the plural forms of such terms. Any agreement or instrument defined or referred to herein or in any agreement or instrument that is referred to herein means such agreement or instrument as from time to time amended, modified or supplemented. References to a Person are also to its permitted successors and assigns.

          (d) Counterparts. This Agreement may be executed in one or more counterparts (including by facsimile), all of which shall be considered one and the same agreement and shall become effective when one or more such counterparts have been signed by each of the parties and delivered to the other parties.

          (e) Entire Agreement; No Third-Party Beneficiaries. This Agreement (a) constitutes the entire agreement, and supersedes all prior agreements and understandings, both written and oral, among the parties with respect to the subject matter of this Agreement and (b) is not intended to confer upon any Person other than the parties hereto and their respective successors and assigns any rights (legal, equitable or otherwise, except the rights conferred upon those Persons specified as proxies in Section 4) or remedies, whether as third party beneficiaries or otherwise.

          (f) Governing Law. This Agreement shall be governed by, and construed in accordance with, the Laws of the State of Delaware, regardless of the Laws that might otherwise govern under applicable principles of conflicts of Laws thereof.

          (g) Severability. If any term or other provision of this Agreement is invalid, illegal or incapable of being enforced by any rule of Law or public policy, all other conditions and terms of this Agreement shall nevertheless remain in full force and effect. Upon such determination that any term or other provision is invalid, illegal or incapable of being enforced, the parties hereto shall negotiate in good faith to modify this Agreement so as to effect the

original intent of the parties as closely as possible to the fullest extent permitted by applicable Law in an acceptable manner and to the end that the transactions contemplated hereby are fulfilled to the extent possible.

          (h) Consent to Jurisdiction; Service of Process; Venue. Each of the parties hereto irrevocably and unconditionally submits to the exclusive jurisdiction of the Delaware Court of Chancery (and if the Delaware Court of Chancery shall be unavailable, any Delaware State court and the Federal court of the United States of America sitting in the State of Delaware) for the purposes of any suit, action or other proceeding arising out of this Agreement or the Merger or any other transaction contemplated by this Agreement (and agrees that no such action, suit or proceeding relating to this Agreement shall be brought by it or any of its Subsidiaries except in such courts). Each of the parties further agrees that, to the fullest extent permitted by applicable Law, service of any process, summons, notice or document by U.S. registered mail to such Person’s respective address set forth above shall be effective service of process for any action, suit or proceeding in the State of Delaware with respect to any matter to which it has submitted to jurisdiction as set forth above in the immediately preceding sentence. Each of the Stockholders hereby appoints the Company as its agent for service of process for any claim, action, suit or other proceeding in Delaware with respect to any matters to which it has submitted to jurisdiction as set forth above. Each of the parties hereto irrevocably and unconditionally waives (and agrees not to plead or claim), any objection to the laying of venue of any action, suit or proceeding arising out of this Agreement or the Merger or any of the other transactions contemplated by this Agreement in the Delaware Court of Chancery (and if the Delaware Court of Chancery shall be unavailable, in any Delaware State court or the Federal court of the United States of America sitting in the State of Delaware) or that any such action, suit or proceeding brought in any such court has been brought in an inconvenient forum.

          (i) Enforcement. The parties agree that irreparable damage would occur in the event that any of the provisions of this Agreement were not performed in accordance with their specific terms or were otherwise breached. It is accordingly agreed that the parties hereto shall be entitled to an injunction or injunctions to prevent breaches of this Agreement and to enforce specifically the terms and provisions of this Agreement in the Delaware Court of Chancery (and if the Delaware Court of Chancery shall be unavailable, in any Delaware State court or the Federal court of the United States of America sitting in the State of Delaware), this being in addition to any other remedy to which they are entitled at Law or in equity.

          (j) Waiver of Jury Trial. Each party hereto hereby waives, to the fullest extent permitted by applicable Law, any right it may have to a trial by jury in respect of any suit, action or other proceeding directly or indirectly arising out of, under or in connection with this Agreement. Each party hereto (a) certifies that no representative, agent or attorney of any other party has represented, expressly or otherwise, that such party would not, in the event of any action, suit or proceeding, seek to enforce the foregoing waiver and (b) acknowledges that it and the other parties hereto have been induced to enter into this Agreement, by, among other things, the mutual waiver and certifications in this Section 8(j).

          (k) Fiduciary Duties. Notwithstanding anything in this Agreement to the contrary:

     (i) each Stockholder makes no agreement or understanding herein in any capacity other than in such Stockholder’s capacity as a record holder and beneficial owner of the Subject Shares and not in such Stockholder’s capacity as a director, officer or employee of the Company or any of its Subsidiaries; and

     (ii) nothing herein shall be construed to limit or affect any actions or inactions by such Stockholder or any representative of Stockholder, as applicable, serving on the Board of Directors or any Subsidiary of the Company or as an officer or fiduciary of the Company or any Subsidiary of the Company, acting in such person’s capacity as a director, officer, employee or fiduciary of the Company or any Subsidiary of the Company.

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          IN WITNESS WHEREOF, Parent has caused this Agreement to be signed by its officer thereunto duly authorized and each Stockholder has signed this Agreement, all as of the date first written above.

[Signature Page to Stockholders Agreement]

[Signature Page to Stockholders Agreement]

[Signature Page to Stockholders Agreement]

Schedule A

						Number of Subject
Name and Address of		Number of Subject Shares				Shares Owned
Stockholder		Owned of Record				Beneficially
Yuchun Lee			111,271				4,458,509
Agustina Sumito Lee			622				622
Agustina Sumito Living Trust			2,192,197				2,192,197
Yuchun Lee 2010 GRAT			1,000,000				1,000,000
Lee Sumito Irrevocable Trust			686,616				686,616
Yuhun Lee Living Trust			300,890				300,890
2001 Lee Charitable Trust			166,913				166,913

Schedule B

		Number of Shares				Number of Shares
Name and Address of		Subject to				Subject to Unvested
Stockholder		Unexercised Options				RSUs
Yuchun Lee			479,999				92,500