<PAGE>

                                                                   Exhibit 10.26



     NEITHER THIS WARRANT NOR THE SHARES ISSUABLE UPON EXERCISE OF THIS WARRANT
HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND NEITHER
THIS WARRANT NOR THE SHARES ISSUABLE UPON EXERCISE OF THIS WARRANT MAY BE SOLD
OR TRANSFERRED UNLESS THE REGISTRATION PROVISIONS OF SAID ACT HAVE BEEN COMPLIED
WITH OR UNLESS COMPLIANCE WITH SUCH PROVISIONS IS NOT REQUIRED.


No. AC-2                                             Dated:  December 9, 1999


                             PRIME RESPONSE, INC.

                                 Common Stock
                               Purchase Warrant


     THIS IS TO CERTIFY THAT, for value received, Andersen Consulting LLP (the
"Initial Warrant Holder"), and its registered successors and permitted assigns
are entitled, subject to the terms and conditions set forth below, to purchase
from PRIME RESPONSE, INC. (f/k/a Prime Response Group, Inc.), a Delaware
corporation (the "Corporation"), at any time or from time to time on and after
the date hereof and prior to 5:00 P.M., Boston, Massachusetts time, on the
Expiration Date (as defined in Section 1 below), all or any portion of the
Warrant Shares (as defined in Section 1), at a purchase price per share equal to
the Exercise Price (as defined in Section 1 below).  The number and character of
the Warrant Shares and the Exercise Price are subject to adjustment as provided
herein.

     1.  Definitions.  As used in this Warrant, the following terms shall have
the respective meanings set forth below or elsewhere in this Warrant as referred
to below:

     "Certificate of Incorporation" shall mean the Certificate of Incorporation
of the Corporation, as amended and in effect from time to time.

     "Common Stock" shall mean shares of the Common Stock of the Corporation,
$0.01 par value per share of the Corporation and shall also include any capital
stock of any class of the Corporation authorized after the date hereof which
shall neither be limited to a fixed sum or percentage of par value in respect of
the rights of the holders  thereof to participate in dividends or any
distribution of earnings or assets (in liquidation or otherwise) of the
Corporation, whether or not such capital stock is entitled to a
<PAGE>

preference in the distribution of assets upon the voluntary or involuntary
liquidation, dissolution or winding up of the Corporation.

     "Corporation" shall mean Prime Response, Inc. and/or any Person that shall
succeed to, or assume the obligations hereunder of, Prime Response, Inc.

     "Derivative Securities" shall mean (i) all shares of stock and other
securities that are, directly or indirectly, convertible into or exchangeable
for shares of Common Stock and (ii) all options, warrants and other rights to
acquire, directly or indirectly, shares of Common Stock or securities, directly
or indirectly, convertible into or exchangeable for shares of Common Stock.

     "Exercise Date" shall have the meaning set forth in Section 2.2 hereof.

     "Exercise Price" shall mean, as of the Initial Exercise Date, the Initial
Exercise Price and after the Initial Exercise Date, the Initial Exercise Price
as adjusted from time to time pursuant to the terms of this Warrant.

     "Expiration Date" shall mean December 9, 1999.

     "Fair Market Value" shall mean (i) the last reported sale price per share
of Stock on the Nasdaq National Market or any national securities exchange in
which such Stock is quoted or listed, as the case may be, on the date
immediately preceding the Exercise Date or, if no such sale price is reported on
such date, such price on the next preceding business day in which such price was
reported, or (ii) if such Stock is not quoted or listed on the Nasdaq National
Market or any national securities exchange, the fair market value of a share of
such Stock, as determined in good faith by the Board of Directors of the
Corporation and based upon the fair market value of the Corporation as a whole,
(and not taking into account any discounts for minority ownership or
restrictions or transfer of capital stock of the Corporation).

     "Holder" shall mean, as applicable, (i) the Initial Warrant Holder, or (ii)
any successor of the Initial Warrant Holder.

     "Initial Exercise Date" shall mean the date on which this Warrant first
vests in accordance with the provisions of the second paragraph of Section 2.1
hereof.

     "Initial Exercise Price" shall mean an amount equal to $7.01 per share.

     "Initial Warrant Holder" shall have the meaning set forth in the first
paragraph of this Warrant.

     "Initial Warrant Shares" shall mean 500,000 shares of Common Stock.

                                      -2-
<PAGE>

     "Issue Date" shall mean the date hereof.

     "Person" shall mean an individual, partnership, corporation, limited
liability company, business trust, joint stock company, trust, unincorporated
association, joint venture, governmental authority or other entity of whatever
nature.

     "Preferred Stock" shall mean the Series A Preferred Stock, the Series B
Preferred Stock and the Series C Preferred Stock and all other capital stock of
the Corporation having a preference on dissolution or liquidation of the
Corporation.

     "Purchase Agreement" shall mean that certain Common Stock and Warrant
Purchase Agreement, dated of December 6, 1999, by and between the Corporation
and Andersen Consulting LLP.

     "Registrable Securities" shall have the meaning ascribed to it in the
Registration Rights Agreement.

     "Registration Rights Agreement" shall mean the Amended and Restated
Registration Rights Agreement, dated as of December 6, 1999, by and among the
Corporation and the other parties thereto.

     "Securities Act" shall mean the Securities Act of 1933, as amended.

     "Series A Preferred Stock" shall mean the Series A Convertible
Participating Preferred Stock of the Corporation, $0.01 par value per share.

     "Series B Preferred Stock" shall mean the Series B Convertible
Participating Preferred Stock of the Corporation, $0.01 par value per share.

     "Series C Preferred Stock" shall mean the Series C Convertible Preferred
Stock of the Corporation, $0.01 par value per share.

     "Stock" shall mean (i) Common Stock, (ii) capital stock of the Corporation
(other than Common Stock) or of any other Person or any other securities of the
Corporation or of any other Person that the Holder is entitled to receive, or
receives, upon exercise of this Warrant, in lieu of or in addition to Common
Stock, and/or (iii) capital stock of the Corporation (other than Common Stock)
or of any other Person or any other securities of the Corporation or of any
other Person that may be issued in replacement of, substitution, exchange or
redemption for, or upon reclassification or conversion of, Common Stock or any
other Stock, in each case whether as a result of a reorganization,
reclassification, merger, consolidation or sale of substantially all of the
assets of the Corporation.

                                      -3-
<PAGE>

     "Warrant" shall have the meaning set forth in the second paragraph of this
Warrant.

     "Warrant Shares" shall mean, at any time, the Initial Warrant Shares after
giving effect to the number of shares of Stock previously purchased by the
Holder pursuant to any and all exercises of this Warrant prior to such time and
after giving effect to all adjustments with respect to the number of Warrant
Shares purchaseable hereunder as provided for herein, including, without
limitation, those set forth in Section 4 hereof, prior to such time.

     2.  Exercise Of Warrant.

     2.1  Method of Exercise.  Subject to and upon all of the terms and
conditions set forth in this Warrant, the Holder may exercise this Warrant, in
whole or in part with respect to any Warrant Shares, at any time and from time
to time during the period commencing on the date that this Warrant vests in
accordance with the second paragraph of this Section 2.1 and ending at 5:00
p.m., Boston, Massachusetts time, on the Expiration Date, by presentation and
surrender of this Warrant to the Corporation at its principal office, together
with (a) a properly completed and duly executed subscription form, in the form
attached hereto, which subscription form shall specify the number of Warrant
Shares for which this Warrant is then being exercised, and (b) payment of the
aggregate Exercise Price payable hereunder in respect of the number of Warrant
Shares being purchased upon exercise of this Warrant.  Payment of such aggregate
Exercise Price shall be made (i) in cash or by money order, certified or bank
cashier's check or wire transfer (in each case in lawful currency of the United
States of America), (ii) by cancellation of indebtedness owing from the
Corporation to the Holder, (iii) if the Common Stock is then traded on the
Nasdaq National Market or a national securities exchange, by cancellation of a
portion of this Warrant exercisable for such number of Warrant Shares as is
determined by dividing (A) the total Exercise Price payable in respect of the
number of Warrant Shares being purchased upon such exercise by (B) the excess of
the Fair Market Value per share of Common Stock as of the Exercise Date (as
defined below) over the Exercise Price per share; if the Holder wishes to
exercise this Warrant pursuant to this clause (iii) with respect to the maximum
number of Warrant Shares purchasable pursuant to this method, then the number of
Warrant Shares so purchased shall be equal to the total number of Warrant
Shares, minus the product obtained by multiplying (x) the total number of
Warrant Shares by (y) a fraction, the numerator of which shall be the Exercise
Price per share and the denominator of which shall be the Fair Market Value per
share of Common Stock as of the Exercise Date, or (iv) any combination of the
methods described in the foregoing clauses (i), (ii) or (iii).

The Warrant will become exercisable ("vest") based on the extent (if any) to
which the Market Capitalization (as defined below) of the Company exceeds the
IPO Capitalization (as defined below) of the Company, in accordance with the
following schedule:

                                      -4-
<PAGE>

        If the Market Capitalization is less than $2 billion, warrants
        to purchase such number of shares of Common Stock as is equal to
        (i) 400,000 divided by (ii) (a) $2 billion minus the IPO
        Capitalization divided by (b) $100 million, will become
        exercisable for each $100 million by which the Market
        Capitalization exceeds the IPO Capitalization.

        If the Market Capitalization is between $2 billion and $3 billion,
        inclusive, warrants to purchase 10,000 shares of Common Stock will
        become exercisable for each $100 million by which the Market
        Capitalization exceeds the IPO Capitalization.

        No additional warrants will become exercisable once the Market
        Capitalization exceeds $3 billion. In no event shall this Warrant become
        exercisable for more than 500,000 shares of Common Stock.

    For purposes of the foregoing, the Market Capitalization shall be measured
on the following dates and on no other dates: December 31, 2000, 2001 and 2002
and on the final day that the Marketing Agreement (as defined below) is in
effect.

    Once this Warrant becomes exercisable with respect to Warrant Shares in
accordance with the foregoing provisions, this Warrant shall not cease to be
exercisable with respect to such Warrant Shares as a result of the Market
Capitalization decreasing below the amount that resulted in this Warrant (or any
portion hereof) becoming exercisable.  Notwithstanding anything to the contrary
contained herein, upon termination of the Marketing Agreement between the
Company and Andersen Consulting LLP ("Andersen") dated the date hereof (the
"Marketing Agreement") at the election of the Company as a result of a breach by
Andersen pursuant to Section 10.2(a) thereof, no further vesting of this Warrant
shall occur, but the Warrant shall remain exercisable during its term to the
extent then vested.

    "Market Capitalization" on any given date shall equal (i) the last sale
price of the Common Stock as reported by the Nasdaq National Market (or, if
applicable, The Nasdaq Stock Market or any national securities exchange on which
the common stock is then traded) on such date, multiplied by (ii) the number of
shares of Common Stock outstanding as of the close of business on such date as
reflected on the stock records of the Company.

    "IPO Capitalization" shall equal (i) the price to public reflected in the
prospectus filed pursuant to Rule 424(b) under the Securities Act relating to
the Company's initial public offering of Common Stock registered under the
Securities Act, multiplied by (ii) the number of shares of Common Stock to be
outstanding after such offering as reflected in such prospectus under the
heading "The Offering."

                                      -5-
<PAGE>

    2.2 Effectiveness of Exercise; Ownership. Each exercise of this Warrant by
        ------------------------------------
the Holder shall be deemed to have been effected immediately prior to the close
of business on the date upon which all of the requirements of Section 2.1 hereof
with respect to such exercise shall have been complied with in full (each such
date, an "Exercise Date"). On the applicable Exercise Date with respect to any
          -------------
exercise of this Warrant by the Holder, the Corporation shall be deemed to have
issued to the Holder, and the Holder shall be deemed to have become the holder
of record and legal owner of, the number of Warrant Shares being purchased upon
such exercise of this Warrant, notwithstanding that the stock transfer books of
the Corporation shall then be closed or that certificates representing such
number of Warrant Shares being purchased shall not then be actually delivered to
the Holder.

     2.3  Delivery of Stock Certificates on Exercise.  As soon as practicable
after the exercise of this Warrant, and in any event within ten (10) days
thereafter, the Corporation, at its expense and in accordance with applicable
securities laws, will cause to be issued in the name of and delivered to the
Holder, or as the Holder may direct (subject in all cases, to the provisions of
Section 9 hereof), a certificate or certificates for the number of Warrant
Shares purchased by the Holder on such exercise, plus, in lieu of any fractional
share to which the Holder would otherwise be entitled, cash equal to such
fraction multiplied by the Fair Market Value.

     2.4  Shares To Be Fully Paid and Nonassessable.  All Warrant Shares issued
upon the exercise of this Warrant shall be validly issued, fully paid and
nonassessable, free of all liens, transfer taxes, charges and other encumbrances
or restrictions on sale (other than those set forth herein) and free and clear
of all preemptive rights.

     2.5  Fractional Shares.  No fractional shares of Stock or scrip
representing fractional shares of Stock shall be issued upon the exercise of
this Warrant.  With respect to any fraction of a share of Stock called for upon
any exercise hereof, the Corporation shall make a cash payment to the Holder as
set forth in Section 2.3 hereof.

     2.6  Issuance of New Warrants; Corporation Acknowledgment.  Upon any
partial exercise of this Warrant, the Corporation, at its expense, will
forthwith and, in any event, within ten (10) days after such partial exercise
issue and deliver to the Holder a new warrant or warrants of like tenor,
registered in the name of the Holder, exercisable, in the aggregate, for the
balance of the Warrant Shares.

     2.7  Payment of Taxes and Expenses.  The Corporation shall pay any
recording, filing, stamp or similar tax which may be payable in respect of any
transfer involved in the issuance of, and the preparation and delivery of
certificates (if applicable) representing, (i) any Warrant Shares purchased upon
exercise of this Warrant and/or (ii) new or replacement warrants in the Holder's
name or the name of any transferee of all or any portion of this Warrant.

                                      -6-
<PAGE>

     3.  Registration and Other Rights.

     (a) Registration Rights.  The Holder of this Warrant shall have the right
to cause the Corporation to register any and all Warrant Shares under the
Securities Act and under any blue sky or securities laws of any jurisdictions
within the United States, at the time and in the manner specified and as
provided for in the Registration Rights Agreement, and any and all Warrant
Shares shall be deemed to be included within the definition of Registrable
Securities for all purposes thereof.

     (b) Purchase Agreement.  Subject to Section 10.4 of this Warrant, for the
purposes of the Purchase Agreement, the shares of Common Stock issuable upon
exercise of this Warrant shall be included for the purposes of determining the
number of shares of Common Stock held by such Holder for all purposes of such
agreement.

     4.  Adjustments.

     4.1  Adjustments for Stock Dividends, Subdivisions and Combinations.

        (a) In the event that, at any time and from time to time after the Issue
Date, the Corporation shall (A) issue any additional shares of Stock as a
dividend or distribution on its outstanding Stock or options, warrants or other
rights to purchase, directly or indirectly, Stock as a dividend or distribution
on its outstanding Stock or securities convertible, directly or indirectly, into
Stock as a dividend or distribution on its outstanding Stock (other than shares
of Stock issued upon conversion of Preferred Stock), (B) subdivide its
outstanding shares of Stock into a greater number of shares of Stock or (C)
combine its outstanding shares of Stock into a smaller number of shares of
Stock, then and in each such event, (x) the Exercise Price shall, simultaneously
with the happening of such event, be adjusted by multiplying the then current
Exercise Price by a fraction, (i) the numerator of which shall be the number of
shares of Stock outstanding immediately prior to such event on a fully-diluted
basis, assuming exercise in full of all options, warrants or other rights to
purchase Stock, directly or indirectly, outstanding immediately prior to such
event and conversion into or exchange for Stock, directly or indirectly, of all
securities convertible into or exchangeable for Stock outstanding immediately
prior to such event, each in accordance with their terms, and (ii) the
denominator of which shall be the number of shares of Stock outstanding
immediately after such event on a fully-diluted basis, assuming exercise in full
of all options, warrants or other rights to purchase Stock, directly or
indirectly, outstanding immediately after such event and conversion into or
exchange for Stock, directly or indirectly, of all securities convertible into
or exchangeable for Stock outstanding immediately after such event, each in
accordance with their terms, and the product so obtained shall thereafter be the
Exercise Price then in effect, and (y) the number of Warrant Shares shall be
adjusted by increasing or decreasing, as the case may be, the number of shares
of Stock included within the Warrant Shares by the percentage increase or
decrease in the total number of shares of Stock outstanding immediately after
such event as compared to

                                      -7-
<PAGE>

the total number of shares of Stock outstanding immediately prior to such event
and the result so obtained shall be the number of Warrant Shares then in effect.

     (b) The Exercise Price and the number of Warrant Shares, as so adjusted,
shall be readjusted in the same manner upon the happening of any successive
event or events described in this Section 4.1.

     4.2  Adjustment for Reorganization, Consolidation or Merger.  In the event
that, at any time or from time to time after the Issue Date, the Corporation
shall (a) effect a reorganization, (b) consolidate with or merge into any other
Person, or (c) sell or transfer all or substantially all of its properties or
assets or more than 50% of the voting capital stock of the Corporation (whether
issued and outstanding, newly issued, from treasury, or any combination thereof)
to any other Person under any plan or arrangement contemplating the
reorganization, consolidation or merger, sale or transfer, or dissolution of the
Corporation, then, in each such case, the Holder, upon the exercise of this
Warrant as provided in Section 2 hereof at any time or from time to time after
the consummation of such reorganization, consolidation, merger or sale or the
effective date of such dissolution (subject to the limitation contained in
Section 4.6, if applicable), as the case may be, shall receive, in lieu of the
Warrant Shares issuable on such exercise immediately prior to such consummation
or such effective date, as the case may be, the Stock and property (including
cash) to which the Holder would have been entitled upon the consummation of such
reorganization, consolidation or merger, or sale or transfer, or in connection
with such dissolution, as the case may be, if the Holder had so exercised this
Warrant immediately prior thereto (assuming the payment by the Holder of the
Exercise Price therefor as required hereby in a form permitted hereby, which
payment shall be included in the assets of the Corporation for the purposes of
determining the amount available for distribution), all subject to successive
adjustments thereafter from time to time pursuant to, and in accordance with,
the provisions of this Section 4.

     4.3  Adjustments for Reclassifications.  If the Common Stock issuable upon
the conversion of this Warrant shall be changed into the same or a different
number of shares of any class(es) or series of stock, whether by
reclassification or otherwise (other than an adjustment under Section 4.1 or a
merger, consolidation, or sale of assets provided for under Section 4.2), then
and in each such event, the Holder hereof shall have the right thereafter to
convert each Warrant Share into the kind and amount of shares of stock and other
securities and property receivable upon such reclassification, or other change
by holders of the number of shares of Common Stock into which such Warrant
Shares would have been convertible immediately prior to such reclassification,
or change, all subject to further adjustment as provided herein.

     4.4  Distributions.  In the event that, at any time or from time to time
after the Issue Date, the Corporation shall make or issue, or shall fix a record
date for the determination of eligible holders entitled to receive, a dividend
or other distribution with respect to Common Stock payable in (i) shares of its
capital stock (other than a stock

                                      -8-
<PAGE>

dividend provided for in Section 4.1), (ii) other securities of the Corporation
or any other Person, (iii) evidences of indebtedness issued by the Company or
any other Person, (iv) options, warrants or rights to subscribe for or purchase
any of the foregoing, or (v) assets (excluding cash dividends) then, in each
such case, the Holder of this Warrant shall receive, in addition to the shares
of Stock issuable upon the exercise of this Warrant prior to such date, and
without the payment of additional consideration therefor, the shares of capital
stock, other securities, evidence of indebtedness, options, warrants or other
rights or assets, as the case may be, to which such Holder would have been
entitled upon such date as if such Holder had exercised this Warrant on the date
hereof and had thereafter, during the period from the date hereof to and
including the date of the actual exercise of this Warrant, retained such shares
and/or all other additional stock available to it as aforesaid during such
period, giving effect to all adjustments pursuant to this Section 4. The Company
shall reserve and set aside, for the life of this Warrant or until exercised in
full, all such distributions to which the Holder is entitled to receive pursuant
to this Section 4.4.

     4.5  Continuation of Terms.  Upon any reorganization, reclassification,
sale, consolidation, merger or other transfer (and any liquidation, dissolution
or winding up of the Corporation following any such transfer) referred to in
this Section 4, this Warrant shall continue in full force and effect and the
terms hereof shall be applicable to the shares of Stock and property (including
cash, where applicable) receivable upon the exercise of this Warrant after the
consummation of such reorganization, reclassification, sale, consolidation,
merger or other transfer or the effective date of liquidation, dissolution or
winding up of the Corporation following any such transfer, as the case may be,
and shall be binding upon the issuer of any such Stock, including, in the case
of any such transfer, the Person acquiring all or substantially all of the
properties or assets or more than 50% of the voting capital stock of the
Corporation (whether issued and outstanding, newly issued or from treasury or
any combination thereof), whether or not such Person shall have expressly
assumed the terms of this Warrant.

     5.  Officer's Certificate as to Adjustments.  In each case of any
adjustment or readjustment in the number and kind of Warrant Shares, or
property, issuable hereunder from time to time, or the Exercise Price, the
Corporation, at its expense, will promptly cause an officer of the Corporation
to compute such adjustment or readjustment in accordance with the terms of this
Warrant and prepare a certificate setting forth such adjustment or readjustment
and showing the facts upon which such adjustment or readjustment is based.  The
Corporation will forthwith send a copy of each such certificate to the Holder in
accordance with Section 10.5 below.

                                      -9-
<PAGE>

     6.  Notices of Record Date, Etc.  In the event of

     (a) any taking by the Corporation of a record of the holders of Stock for
the purpose of determining the holders thereof who are entitled to receive any
shares of Stock as a dividend or other distribution or pursuant to a stock
split, or

     (b) any reorganization of the Corporation, or any sale or transfer, in a
single transaction or a series of related transactions, of all or substantially
all the assets of the Corporation to, or the consolidation or merger of the
Corporation with or into, any other Person, or

     (c) any voluntary or involuntary dissolution, liquidation or winding-up of
the Corporation, or

     (d) any sale, in a single transaction or a series of related transactions,
of a majority of the Corporation's voting stock (whether newly issued, or from
treasury, or previously issued and then outstanding, or any combination
thereof),

then and in each such event the Corporation will mail or cause to be mailed to
the Holder a notice specifying (i) the date on which any such record is to be
taken for the purpose of such dividend, distribution or stock split, and stating
the amount and character of such dividend, distribution or stock split, or (ii)
the date on which any such reorganization, transfer, consolidation, merger,
dissolution, liquidation or winding-up is to take place, and the time, if any is
to be fixed, as of which the holders of record of any one or more classes of
Stock shall be entitled to exchange their shares of Stock for securities or
other property deliverable on such reorganization, transfer, consolidation,
merger, dissolution, liquidation or winding-up, or (iii) the date on which any
such sale of a majority of the Corporation's voting stock is to take place and
the material terms thereof, as the case may be.  Such notice shall be mailed at
least ten (10) days prior to the date specified in such notice on which any such
action is to be taken.

     7.  Exchange of Warrant.  Subject to the provisions of Section 9 hereof (if
and to the extent applicable), this Warrant shall be exchangeable, upon the
surrender hereof by the Holder at the principal office of the Corporation, for
new warrants of like tenor, each registered in the name of the Holder or in the
name of such other Persons as the Holder may direct.  Each of such new warrants
shall be exercisable for such number of Warrant Shares as the Holder shall
direct, provided that all of such new warrants shall represent, in the
aggregate, the right to purchase the same number of Warrant Shares and cash,
securities or other property, if any, which may be purchased by the Holder upon
exercise of this Warrant at the time of its surrender.

     8.  Replacement of Warrant.  On receipt of evidence reasonably satisfactory
to the Corporation of the loss, theft, destruction or mutilation of this Warrant
and, in the case of any such loss, theft or destruction of this Warrant, on
delivery of a customary

                                      -10-
<PAGE>

affidavit of the Holder and an indemnity agreement or, in the case of any such
mutilation, on surrender and cancellation of this Warrant, the Corporation at
its expense will execute and deliver, in lieu thereof, a new warrant of like
tenor.

     9.  Transfer Provisions, etc.

     9.1  Legends.

        (a) Each certificate representing any Warrant Shares issued upon
exercise of this Warrant shall bear the following legend:

        THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933,
     AS AMENDED, AND MAY BE TRANSFERRED ONLY PURSUANT TO AN EFFECTIVE
     REGISTRATION STATEMENT FOR SUCH SECURITIES UNDER THE SECURITIES ACT OF
     1933, AS AMENDED, OR IN ACCORDANCE WITH AN APPLICABLE EXEMPTION FROM THE
     REGISTRATION REQUIREMENTS OF THE SECURITIES ACT OF 1933, AS AMENDED.

        (b) Each certificate representing any shares of Stock issued from time
to time upon exercise of this Warrant shall also bear any legend required under
any applicable state securities or blue sky laws.

     9.2  Mechanics of Transfer.  Any transfer of all or any portion of this
Warrant, or of any interest therein, that is otherwise in compliance with
applicable law shall be effected by surrendering this Warrant to the Corporation
at its principal office, together with (i) a duly executed form of assignment,
in the form attached hereto, (ii) payment of any applicable transfer taxes, if
any.  In the event of any such transfer of this Warrant, in whole, the
Corporation shall issue a new warrant of like tenor to the transferee,
representing the right to purchase the same number of Warrant Shares, and cash,
securities or other property, if any, which were purchasable by the Holder upon
exercise of this Warrant at the time of its transfer.  In the event of any such
transfer of any portion of this Warrant, (i) the Corporation shall issue a new
warrant of like tenor to the transferee, representing the right to purchase the
same number of Warrant Shares, and cash, securities or other property, if any,
which were purchasable by the Holder upon exercise of the transferred portion of
this Warrant at the time of such transfer, and (ii) the Corporation shall issue
a new warrant of like tenor to the Holder, representing the right to purchase
the number of Warrant Shares, and cash, securities or other property, if any,
purchasable by the Holder upon exercise of the portion of this Warrant not
transferred to such transferee.  Until this Warrant or any portion thereof is
transferred on the books of the Corporation, the Corporation may treat the
Holder as the absolute holder of this Warrant and all right, title and interest
therein for all purposes, notwithstanding any notice to the contrary.

                                      -11-
<PAGE>

     9.3.  Restrictions on Transfer.  Subject to compliance with applicable
securities laws and any other contractual restrictions to which the Holder may
be subject, this Warrant, and any portion hereof, and the Warrant Shares may be
transferred by the Holder in its sole discretion at any time to affiliates of
the Holder without the consent of the Corporation.  Except as permitted pursuant
to the foregoing sentence, this warrant may not be transferred without the
consent of the Corporation.

     10.  General.

     10.1  Statement on Warrant.  Irrespective of any adjustments in the
Exercise Price or the number or kind of Warrant Shares, this Warrant may
continue to express the same kind of Warrant Shares as are stated on the front
page hereof.

     10.2  Authorized Shares; Reservation of Shares for Issuance.  At all times
while this Warrant is outstanding, the Corporation shall maintain its corporate
authority to issue, and shall have authorized and reserved for issuance upon
exercise of this Warrant, such number of shares of Stock as shall be sufficient
to perform its obligations under this Warrant (after giving effect to any and
all adjustments to the number and kind of Warrant Shares purchasable upon
exercise of this Warrant).

     10.3  No Impairment.  The Corporation will not, by amendment of its
Certificate of Incorporation or through any reorganization, transfer of assets,
consolidation, merger, dissolution, issuance or sale of securities, sale or
other transfer of any of its assets or properties, or any other voluntary
action, avoid or seek to avoid the observance or 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 hereunder against
impairment.  Without limiting the generality of the foregoing, the Corporation
(a) will not increase the par value of any shares of Stock receivable upon the
exercise of this Warrant above the amount payable therefor on such exercise, and
(b) will take all action that may be necessary or appropriate in order that the
Corporation may validly and legally issue fully paid and nonassessable shares of
Stock on the exercise of this Warrant.

     10.4  No Rights as Stockholder.  The Holder shall not be entitled to vote
or to receive dividends or to be deemed the holder of Stock that may at any time
be issuable upon exercise of this Warrant for any purpose whatsoever, nor shall
anything contained herein be construed to confer upon the Holder any of the
rights of a stockholder of the Corporation until the Holder shall have exercised
this Warrant and been issued Warrant Shares in accordance with the provisions
hereof.

     10.5  Notices.  All notices, demands, requests, certificates or other
communications under this Warrant shall be in writing and shall be either mailed
by certified mail, postage prepaid, in which case such notice, demand, request,
certificate or

                                      -12-
<PAGE>

other communications shall be deemed to have been given three (3) days after the
date on which it is first deposited in the mails, or hand delivered or sent by
facsimile transmission, by tested or otherwise authenticated telex or cable or
by private expedited courier for overnight delivery with signature required, in
each such case, such notice, demand, request, certificate or other
communications being deemed to have been given upon delivery or receipt, as the
case may be:

     (i) if to the Corporation, Prime Response, Inc., 150 Cambridge Park Drive,
Cambridge, MA  02140, Attention: President, or at such other address as the
Corporation may have furnished in writing to the Holder; and

     (ii) if to the Holder, at the Holder's address appearing in the books
maintained by the Corporation.

     10.6  Amendment and Waiver.  No failure or delay of the Holder in
exercising any power or right hereunder shall operate as a waiver thereof, nor
shall any single or partial exercise of any such right or power, or any
abandonment or discontinuance of steps to enforce such a right or power,
preclude any other or further exercise thereof or the exercise of any other
right or power.  The rights and remedies of the Holder are cumulative and not
exclusive of any rights or remedies which it would otherwise have.  The
provisions of this Warrant may be amended, modified or waived with (and only
with) the written consent of the Corporation and the Holder.

     10.7  Governing Law.  This Warrant shall be governed by, and construed and
enforced in accordance with, the laws of the Commonwealth of Massachusetts.

     10.8  Covenants To Bind Successor and Assigns.  All covenants,
stipulations, promises and agreements in this Warrant contained by or on behalf
of the Corporation shall bind its successors and assigns, whether so expressed
or not.

     10.9  Severability.  In case any one or more of the provisions contained in
this Warrant shall be invalid, illegal or unenforceable in any respect, the
validity, legality and enforceability of the remaining provisions contained
herein shall not in any way be affected or impaired thereby.  The parties shall
endeavor in good faith negotiations to replace the invalid, illegal or
unenforceable provisions with valid provisions the economic effect of which
comes as close as possible to that of the invalid, illegal or unenforceable
provisions.

     10.10  Construction.  The definitions of this Warrant shall apply equally
to both the singular and the plural forms of the terms defined.  Wherever the
context may require, any pronoun shall include the corresponding masculine,
feminine and neuter forms.  The section and paragraph headings used herein are
for convenience of reference only, are not part of this Warrant and are not to
affect the construction of or be taken into consideration in interpreting this
Warrant.

                                      -13-
<PAGE>

     10.11  Remedies.  The Holder, in addition to being entitled to exercise all
rights granted by law, including recovery of damages, will be entitled to
specific performance of its rights under this Warrant.  The Corporation agrees
that monetary damages would not be adequate compensation for any loss incurred
by reason of a breach by it of the provisions of this Warrant and hereby agrees
to waive the defense in any action for specific performance that a remedy at law
would be adequate.  In any action or proceeding brought to enforce any provision
of this Warrant or where any provision hereof is validly asserted as a defense,
the successful party to such action or proceeding shall be entitled to recover
reasonable attorneys' fees in addition to any other available remedy.

[rest of page intentionally left blank]

                                      -14-
<PAGE>

     IN WITNESS WHEREOF, the Corporation has caused this Common Stock Purchase
Warrant to be executed as an instrument under seal in its corporate name by one
of its officers thereunto duly authorized, all as of the day and year first
above written.

                                         PRIME RESPONSE, INC.
[Corporate Seal]

                                         By: /s/ Frederick H. Phillips
                                            ---------------------------------
                                         Name: Frederick H. Phillips
                                         Title: Secretary, Treasurer,
                                                Senior Vice President and
                                                Chief Financial Officer

                                      -15-
<PAGE>

                             FORM OF SUBSCRIPTION


                   (To be executed upon exercise of Warrant)


To:  PRIME RESPONSE, INC.

     The undersigned hereby irrevocably elects to exercise the right of purchase
represented by the attached Warrant for, and to exercise thereunder, _______
shares of Common Stock, $.01 par value per share ("Common Stock"), of Prime
Response, Inc., a Delaware corporation, and tenders herewith payment of
$__________, representing the aggregate purchase price for such shares based on
the price per share provided for in such Warrant.  Such payment is being made in
accordance with [Section 2.1(b)(i)] [Section 2.1(b)(ii)] [Section 2.1(b)(iii)]
of the attached Warrant.

     Please issue a certificate or certificates for such shares of Common Stock
in the following name or names and denominations and deliver such certificate or
certificates to the person or persons listed below at their respective addresses
set forth below:

Dated:


                                   (Address)

     If said number of shares of Common Stock shall not be all the shares of
Common Stock issuable upon exercise of the attached Warrant, a new Warrant is to
be issued in the name of the undersigned for the balance remaining of such
shares of Common Stock less any fraction of a share of Common Stock paid in
cash.


Dated:  ____________, ____
                                                NOTE: The above signature should
                                                correspond exactly with the name
                                                on the face of the attached
                                                Warrant or with the name of the
                                                assignee appearing in the
                                                assignment form below.
<PAGE>

                              FORM OF ASSIGNMENT


                  (To be executed upon assignment of Warrant)


     For value received, _____________________________________ hereby sells,
assigns and transfers unto _________________ the attached Warrant [__% of the
attached Warrant], together with all right, title and interest therein, and does
hereby irrevocably constitute and appoint ___________________________ attorney
to transfer said Warrant [said percentage of said Warrant] on the books of Prime
Response, Inc., a Delaware corporation, with full power of substitution in the
premises.

     If not all of the attached Warrant is to be so transferred, a new Warrant
is to be issued in the name of the undersigned for the balance of said Warrant.



Dated:  ____________, ____
                                                        NOTE: The above
                                                        signature should
                                                        correspond exactly with
                                                        the name on the face of
                                                        the attached Warrant.