Document:

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                                                                   EXHIBIT 10.17

                                PROMISSORY NOTE
                                   NEGOTIABLE

US$111,271.00                                                    January 3, 2000
                                                           San Diego, California

FOR VALUE RECEIVED, the undersigned ("Maker") promises to pay to the order of
WebSideStory, Inc., a corporation organized under the laws of the state of
California ("Holder"), at 10182 Telesis Court, San Diego, California or at such
other place as the Holder hereof may from time to time designate, the principal
sum of ONE HUNDRED ELEVEN THOUSAND TWO HUNDRED SEVENTY-ONE dollars
($111,271.00), with interest on the unpaid principal balance from time to time
outstanding, computed on the basis of a three hundred sixty (360) day year,
actual days elapsed, at a rate (the "Interest Rate") equal to 6.5% per annum.
Payment of principal and interest shall be made in the lawful money of the
United States which shall be legal tender for public and private debts at the
time of payment. The entire outstanding principal balance and all accrued but
unpaid interest shall be due and payable on the third anniversary of this note
(the "Due Date"). Each payment hereunder shall be credited first to interest
then accrued and the remainder to unpaid principal, and interest shall thereupon
cease upon the principal so credited, Maker shall have the right to repay all or
a portion of the outstanding principal and/or interest hereunder at any time or
times prior to the Due Date, without penalty.

This note shall automatically become due and payable prior to the Due Date,
without notice or demand and without the need for any action or election by the
Holder hereof, upon the occurrence at any time of any of the following events of
default:

        (1) The making of an assignment for the benefit of creditors by any
party liable for the payment of this note, whether as maker, endorser,
guarantor, surety, or otherwise, or the voluntary appointment (at the request of
any such party or with the consent of any such party) of a receiver, custodian,
liquidator or trustee in bankruptcy of any such party's property or the filing
by any such party of a petition in bankruptcy or other similar proceeding under
law for relief of debtors; or

        (2) The filing (other than by Holder) against any party liable for the
payment of this note, whether as maker, endorser, surety, or otherwise, of a
petition in bankruptcy or other similar proceeding under law for relief of
debtors, or the involuntary appointment of a receiver, custodian, liquidator or
trustee in bankruptcy of the property of any such party, and such petition or
appointment is not vacated or discharged within ninety (90) calendar days after
the filing or making thereof.

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If this note is not paid when due, whether at the Due Date or by acceleration,
the undersigned promises to pay all costs of collection, including without
limitation reasonable attorneys' fees, and all expenses in connection with the
protection or realization of any collateral securing this note incurred by the
Holder hereof on account of such collection, whether or not suit is filed
hereon; such costs and expenses shall include without limitation all costs,
attorneys' fees and expenses incurred by the Holder hereof in connection with
any insolvency, bankruptcy, reorganization, arrangement or other similar
proceedings involving the undersigned or involving any endorser hereof, which in
any way affect the exercise by the Holder hereof of its rights and remedies
under this note or under any security agreement, pledge agreement, cash
collateral agreement or other agreement securing this note.

Presentment, demand, protest, notices of protest, dishonor and non-payment of
this note and all notices of every kind are hereby waived. To the extent
permitted by applicable law, the defense of the statute of limitations is hereby
waived by the undersigned.

No single or partial exercise of any power hereunder or under any security
agreement, pledge agreement, cash collateral agreement or other agreement
securing this note shall preclude other or further exercise thereof or the
exercise of any other power. The Holder hereof shall at all times have the right
to proceed against any portion of the security held for this note in such order
and in such manner as the Holder may deem fit, without waiving any rights with
respect to any other security. No delay or omission on the part of the Holder
hereof in exercising any right hereunder shall operate as a waiver of such right
or of any other right under this note. The release of any party liable on this
note shall not operate to release any other party liable hereon.

This note may be prepaid in whole or in part at any time without premium or
penalty. Partial prepayments of principal shall not postpone or delay the date
of any subsequent payments of principal or change the amount of such payments.

 The payment obligations of both principal and interest represented by this note
 will be forgiven in full, and this note will be returned to Maker promptly, if
 and when any of the following events occurs on or before the Due Date;

1       a voluntary sale by Holder's shareholders of a majority of the Holder's
        common stock;

2       a voluntary sale of substantially all assets of Holder;

3       Holder has cash and cash equivalents in aggregate in excess of $4
        million;

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4       Constructive Termination as defined in the Stock Option Agreement of
        December 20, 1999 between Maker and Holder.

Notwithstanding the fact that Holder has cash and cash equivalents in excess of
$4 million (the "Liquidity Condition"), if Holder is in registration for or
shall have completed an initial public offering of its equity securities prior
to December 31, 2000, forgiveness of such payment obligations shall not be
forgiven upon occurrence of the Liquidity Condition, but rather such
obligations shall be forgiven on a pro-rata basis over twelve months commencing
the date such public offering is completed or January 1, 2001, whichever is
earlier.

Any notices required to be given hereunder shall be deemed delivered five (5)
days after such notice in writing is placed in the United States Mail, postage
prepaid to the following addresse(s):

                   If to Holder:
                   WebSideStory
                   10182 Telesis Court
                   San Diego, CA 92121

                   Attn: legal department

                   If to Maker:
                   John Hentrich
                   4778 Keswick Court
                   San Diego CA 92130

The term "Holder" shall include all of Holder's successors and assigns to whom
the benefits of this note shall inure.

In the event any provision of this note is held to be invalid, illegal or
otherwise unenforceable in any respect, such provision shall be construed as
containing the maximum valid, legal and enforceable terms and conditions, and
all other provisions of this note shall remain in full force and effect to the
maximum extent permitted by law.

Any provision of this note that is prohibited or unenforceable in any
jurisdiction shall, as to such jurisdiction, be ineffective to the extent of
such prohibition or unenforceability without invalidating the remaining
provisions of this note, and such prohibition or unenforceability in any
jurisdiction shall not invalidate, or render unenforceable such provision in any
other jurisdiction.

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This note has been executed and delivered by the undersigned in the State of
California and is to be governed by and construed in accordance with the laws of
the State of California without regard to its conflicts of laws rules. In any
action brought under or arising out of this note, the undersigned hereby
consents to the jurisdiction of any competent court within the State of
California and consents to service of process by any means authorized by the law
of that State. This note may be modified, amended or terminated only by a
writing signed by both the Holder and the Maker.

                                          "MAKER"

                                           /s/ JOHN HENTRICH
                                          ------------------------------
                                          John Hentrich

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                                                                   EXHIBIT 10.18

                                 PROMISSORY NOTE

$1,390,887.40______________                                San Diego, California
                                                               February 28, 2000

         FOR VALUE RECEIVED, the undersigned hereby unconditionally promises to
pay to the order of WEBSIDESTORY, INC., a California corporation (the
"Company"), at 6450 Lusk Blvd., Suite E-205, San Diego, California, or at such
other place as the holder hereof may designate in writing, in lawful money of
the United States of America and in immediately available funds, the principal
sum of One Million Three Hundred Ninety Thousand Eight Hundred Eighty Seven
Dollars and Forty Cents ($1,390,887.40) together with interest accrued from the
date hereof on the unpaid principal at the rate of 6.5% per annum, or the
maximum rate permissible by law (which under the laws of the State of California
shall be deemed to be the laws relating to permissible rates of interest on
commercial loans), whichever is less, as follows:

PRINCIPAL REPAYMENT. The outstanding principal amount hereunder shall be due and
payable in full on February 27, 2004; and

INTEREST PAYMENTS. Interest shall be payable annually in arrears and shall be
calculated on the basis of a 360-day year for the actual number of days elapsed;

provided, however, that one twenty-fourth (1/24th) of the principal payment and
all accrued interest of this Note will be forgiven on a monthly basis commencing
April 1, 2000 through March 1, 2002, unless the undersigned has voluntarily
resigned as an employee of Holder, in which case forgiveness of the payment
obligations shall discontinue and the balance of the Principal of this Note and
shall be payable on February 27, 2004 and Interest thereon shall be payable as
set forth above; provided further, however, that all payment obligations of
Principal and Interest of this Note shall be immediately be forgiven in full,
and this Note will be returned promptly to the undersigned, if and when any of
the following events occur: (1) a Change of Control or Constructive Termination
as defined in the Employment Agreement between Maker and the undersigned dated
February 28, 2000 or (2) the Holder has cash and cash equivalents equal to or
exceeding four million dollars ($4,000,000); provided further, however, that if
Holder is in registration for or shall have completed an initial public offering
of its equity securities prior to December 31, 2000, accelerated forgiveness of
the payment obligations because of (2), above, shall not occur assuming such
offering is completed by such date.

         This Note may be prepaid at any time without penalty. All money paid
toward the satisfaction of this Note shall be applied first to the payment of
interest as required hereunder and then to the retirement of the principal.

         The full amount of this Note is secured by a pledge of shares of Common
Stock of the Company, and is subject to all of the terms and provisions of the
Early Exercise Stock Purchase

                                       1
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Agreement and Stock Pledge Agreement of even date herewith between the
undersigned and the Company.

         The undersigned hereby represents and agrees that the amounts due under
this Note are not consumer debt, and are not incurred primarily for personal,
family or household purposes, but are for business and commercial purposes only.

         The undersigned hereby waives presentment, protest and notice of
protest, demand for payment, notice of dishonor and all other notices or demands
in connection with the delivery, acceptance, performance, default or endorsement
of this Note.

         The holder hereof shall be entitled to recover, and the undersigned
agrees to pay when incurred, all costs and expenses of collection of this Note,
including without limitation, reasonable attorneys' fees.

         This Note shall be governed by, and construed, enforced and interpreted
in accordance with, the laws of the State of California, excluding conflict of
laws principles that would cause the application of laws of any other
jurisdiction.

                                       Signed   /s/ JOHN J. HENTRICH

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