<PAGE>   1
                                                                  EXHIBIT 10.2.1


        THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
        SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, PLEDGED, OR
        OTHERWISE TRANSFERRED WITHOUT AN EFFECTIVE REGISTRATION THEREOF UNDER
        SUCH ACT OR AN OPINION OF COUNSEL, SATISFACTORY TO THE CORPORATION AND
        ITS COUNSEL, THAT SUCH REGISTRATION IS NOT REQUIRED.


                               WebSideStory, Inc.

                       NONSTATUTORY STOCK OPTION AGREEMENT


This Stock Option Agreement is made and entered into this day of _____, pursuant
to the WebSideStory, Inc. 1999 Stock Option Plan (the "Plan"). Any terms not
defined in this Agreement will have the meanings given to them in the Plan. The
Committee administering the Plan has decided to make the following grant of a
nonstatutory stock option ("Stock Option") to purchase shares of the common
stock of the Corporation to (the "Optionee"), on the terms and conditions set
forth below to which Optionee accepts and agrees:

        1. Stock Options Granted:


<TABLE>
<S>                                                       <C>
                      Number of Shares Subject to Option  _______________
                      Date of Grant                       _______________
                      Vesting Commencement Date           _______________
                      Exercise Price Per Share            $______________
                      Expiration Date                     _______________
</TABLE>


        2. The Stock Option is granted pursuant to the Plan to purchase the
number of shares of authorized but unissued common stock of the Corporation
specified in Section 1 (the "Shares"). The Stock Option will expire, and all
rights to exercise it will terminate on the Expiration Date, except that the
Stock Option may expire earlier as provided in the Plan. The number of shares
subject to the Stock Option granted pursuant to this Agreement will be adjusted
as provided in the Plan. This Stock Option is intended by the Corporation and
the Optionee to be a Nonstatutory Stock Option and does not qualify for any
special tax benefits to the Optionee and is not subject to Section 7 of the
Plan.

        3. This Stock Option will be exercisable in all respects in accordance
with the terms of the Plan which are incorporated herein by this reference and
will be exercised by Optionee delivering to the Corporation a fully executed
copy of the attached Notice of Exercise/Stock Purchase Agreement and the
Purchase Price. Optionee acknowledges having received and read a copy of the
Plan. All shares of the Corporation's common stock issued pursuant to the
exercise





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of this Stock Option will be subject to the Corporation's Right of Repurchase
and Right of First Refusal as set forth in Sections 11 and 12 of the Plan.

        4. Optionee will have the right to exercise the Stock Option in
accordance with the following schedule:

               (a) The Stock Option may not be exercised in whole or in part at
any time prior to the first anniversary of the Vesting Commencement Date.

               (b) Optionee may exercise the Stock Option as to one third of the
Shares on or after the first anniversary of the Vesting Commencement Date.

               (c) Optionee may exercise the Stock Option as to an additional
1/12th of the Shares at the end of each of the full calendar quarter commencing
with the 5th full calendar quarter following the Vesting Commencement Date.

               (d) The right to exercise the Stock Option will be cumulative.
Optionee may buy all, or from time to time any part, of the maximum number of
shares which are exercisable under the Stock Option, but in no case may Optionee
exercise the Stock Option with regard to a fraction of a share, or for any share
for which the Stock Option is not exercisable.

        5. The Optionee agrees to comply with all laws, rules, and regulations
applicable to the grant and exercise of the Stock Option and the sale or other
disposition of the common stock of the Corporation received pursuant to the
exercise of such Stock Option.

        6. The Stock Option will not become exercisable unless and until the
shares exercisable under the Stock Option have been qualified under the
California Corporate Securities Law of 1968 pursuant to a permit application
filed with the California Department of Corporations or unless the exercise is
otherwise exempt from the qualification requirements of such law. The Stock
Option is conditioned on the Optionee's representation, which Optionee hereby
confirms as of the date of this Agreement and which Optionee must confirm as of
the date of any exercise of all or any part of the Stock Option, that:

               (a) Optionee understands that both this Stock Option and any
shares purchased upon its exercise are securities, the issuance of which require
compliance with state and federal securities laws;

               (b) Optionee understands that neither the Options nor the Shares
have been registered under the Securities Act of 1933 (the "Securities Act") in
reliance upon a specific exemption contained in the Securities Act which depends
on Optionee's bona fide investment intention in acquiring these securities; that
Optionee's intention is to hold these securities for Optionee's own benefit for
an indefinite period; that Optionee has no present intention of selling or
transferring any part thereof (recognizing that the Stock Option is not
transferable) and that certain restrictions may exist on transfer of the shares
issued upon exercise of the Stock Option;

               (c) Optionee understands that the Shares issued upon exercise of
this Stock Option, in addition to other restrictions on transfer, must be held
indefinitely unless subsequently registered under the Securities Act, or unless
an exemption from registration is available; that





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Rule 701 and Rule 144, two exemptions from registration which may be available,
are only available after the satisfaction of certain conditions and require the
presence of a U.S. public market for such Shares; that no certainty exists that
a U.S. public market for the Shares will exist, and that otherwise Optionee may
have to sell the Shares pursuant to another exemption from registration which
exemption may be difficult to satisfy; and

               (d) The Corporation will not be under any obligation to issue any
Shares upon the exercise of this Stock Option unless and until the Corporation
has determined that:

                      (i) it and Optionee have taken all actions required to
register such Shares under the Securities Act, or to perfect an exemption from
the registration requirements thereof;

                      (ii) any applicable listing requirement of any stock
exchange on which such Shares are listed has been satisfied; and

                      (iii) all other applicable provisions of state and federal
law have been satisfied.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]





<PAGE>   4
IN WITNESS WHEREOF, each of the parties hereto has executed this Stock Option
Agreement, in the case of the Corporation by its duly authorized officer, as of
the date and year written above.


OPTIONEE                               WebSideStory, Inc.


                                       By:
-------------------------------           ----------------------------
         (signature)                             (signature)


                                       Its:
-------------------------------             ---------------------------
    (Type or Print Name)


Address:
         ----------------------


                      [SIGNATURE PAGE TO WebSideStory, Inc.
                      NONSTATUTORY STOCK OPTION AGREEMENT]





<PAGE>   5
                               WebSideStory, Inc.
                 NOTICE OF EXERCISE AND STOCK PURCHASE AGREEMENT

                                 (NONSTATUTORY)



THIS NOTICE OF EXERCISE AND STOCK PURCHASE AGREEMENT (the "Stock Purchase
Agreement") is delivered pursuant to a Non-Statutory Stock Option Agreement (the
"Option Agreement") dated ______________, 19__, between WebSideStory, Inc., a
California corporation (the "Corporation"), and the undersigned ("Purchaser").
The capitalized terms used in this Stock Purchase Agreement and not otherwise
defined have the meanings specified for such terms in the Corporation's 1999
Stock Option Plan (the "Plan").

        1. Notice of Exercise. Purchaser has a Nonstatutory Option (the
"Option") to acquire shares of Common Stock, pursuant to the Option Agreement.
Purchaser hereby elects to purchase the number of shares of Common Stock set
forth opposite the undersigned's name below, at the exercise price per share
specified in the Option Agreement, for an aggregate purchase price in an amount
equal to the amount set forth opposite the undersigned's name below, and hereby
so notifies the Corporation. Purchaser understands that the Option may only be
exercised to the extent the Option is exercisable in accordance with Section 4
of the Option Agreement, and acknowledges that this exercise is subject to the
limitations and conditions on exercise set forth in the Option Agreement and in
the Plan.

        2. Purchase and Sale. Subject to the terms and conditions set forth in
this Purchase Agreement, the Option Agreement, and the Plan, the Corporation
hereby sells to Purchaser and Purchaser hereby acquires from the Corporation the
number of shares set forth opposite the undersigned's name below (the "Purchased
Shares") of the Common Stock represented by the Option, at the exercise price
per share specified in the Option Agreement, for an aggregate purchase price in
an amount equal to the amount set forth opposite the undersigned's name below.
Purchaser hereby delivers to the Corporation cash, a check or such other
consideration permitted under the Plan in the amount of such purchase price and
the amount of the estimated withholding taxes which apply to the exercise. The
number of Shares that may be acquired pursuant to the Option is reduced by the
number of Purchased Shares hereby purchased and sold.

        3. Representations and Warranties of Purchaser. In connection with its
purchase of the Purchased Shares, Purchaser hereby represents, acknowledges, and
warrants to the Corporation as follows:

               (a) VESTING OF SHARES PURSUANT TO SECTION 4 OF THE OPTION
AGREEMENT IS EARNED ONLY BY CONTINUING AS AN EMPLOYEE OR AS A CONSULTANT OF THE
CORPORATION AT THE WILL OF THE CORPORATION (NOT THROUGH THE ACT OF BEING HIRED,
ENGAGED, BEING GRANTED AN OPTION, OR BEING SOLD SHARES HEREUNDER). THIS STOCK
PURCHASE AGREEMENT, THE TRANSACTIONS CONTEMPLATED UNDER IT AND THE VESTING
SCHEDULE SET FORTH IN THE OPTION AGREEMENT DO NOT CONSTITUTE AN EXPRESS OR





<PAGE>   6
IMPLIED PROMISE OF CONTINUED ENGAGEMENT FOR THE VESTING PERIOD, FOR ANY PERIOD,
OR AT ALL.

               (b) Purchaser acknowledges receipt of a copy of the Plan, which
is attached to the Option Agreement, and represents that Purchaser has reviewed
the Plan, the Option Agreement and this Purchase Agreement in their entirety,
has had an opportunity to obtain the advice of counsel prior to executing this
Purchase Agreement, fully understands all provisions of this Purchase Agreement,
the Option Agreement, and the Plan.

               (c) Purchaser hereby agrees to accept as binding, conclusive and
final all decisions or interpretations of the Board or the Committee, if one has
been appointed by the Board, regarding any questions arising under the Plan.

        4. Entire Agreement. This Agreement, together with the Plan and the
Option Agreement, constitutes the entire agreement among the parties relating to
the subject matter of this Agreement.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]





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IN WITNESS WHEREOF, this Stock Purchase Agreement is entered into and effective
as of the date first set forth above.

PURCHASER


By:
   -----------------------------------------
No. of Shares:
              ------------------------------
Total Purchase Price:
                     -----------------------
Print Name:
           ---------------------------------
Address:
        ------------------------------------

Soc. Sec. No.
             -------------------------------

WebSideStory, Inc.


By:
   -----------------------------------------
Name:
     ---------------------------------------
Title:
      --------------------------------------

Date of Acceptance:
                   -------------------------


            [SIGNATURE PAGE TO WebSideStory, INC. NONSTATUTORY OPTION
                NOTICE OF EXERCISE AND STOCK PURCHASE AGREEMENT]






<PAGE>   8
                                CONSENT OF SPOUSE



The undersigned spouse of Purchaser has read and hereby approves the Option
Agreement and the foregoing Stock Purchase Agreement. In consideration of the
Corporation's granting my spouse the right to purchase the shares of the
Corporation's Common Stock as set forth in the Option Agreement and the Stock
Purchase Agreement, the undersigned hereby agrees to be irrevocably bound by the
Option Agreement and the Stock Purchase Agreement and further agrees that any
community property interest will be similarly bound by the Option Agreement and
the Stock Purchase Agreement. I hereby appoint my spouse as my attorney-in-fact
with respect to any amendment or exercise of any rights under the Option
Agreement and the Stock Purchase Agreement.


------------------------------
Spouse of Purchaser