SECOND AMENDMENT TO OFFICE LEASE

EXHIBIT 10.21

SECOND AMENDMENT TO OFFICE LEASE

     This SECOND AMENDMENT TO OFFICE LEASE (this “Second Amendment”) is entered into as of the 7 ^th day of December, 2005 (the “Effective Date”), by and between SEAVIEW PFG, LLC, a Delaware limited liability company (“Landlord”), and WEBSIDESTORY, INC., a California corporation (“Tenant”), with reference to the following facts:

RECITALS

     A. Landlord’s predecessor-in-interest, LNR Seaview, Inc., a California corporation ( “LNR” ) and Tenant previously entered into that certain Office Lease dated as of August 23, 1999 (the “Original Lease” ), whereby Tenant leased certain office space (“Premises”) in the Building located at 10182 Telesis Court, San Diego, California 92121 (the “Building”) also known as Seaview Corporate Center, as the same is more particularly described in the Original Lease.

     B. LNR and Tenant also previously entered into that certain First Amendment to Lease (the “First Amendment”) dated as of July 3, 2001 amending certain terms of the Lease. The Original Lease and First Amendment are hereinafter collectively referred to as the “Lease.”

     C. LNR’s interest as landlord under the Lease was previously assigned to Landlord by that certain Assignment of Leases dated April 17, 2002.

     D. Landlord and Tenant now desire to extend the term of the Lease and to further amend certain provisions of the Lease upon the terms set forth herein.

     E. Terms used herein beginning with capital letters and not otherwise defined herein shall have the meanings given to them in the Lease.

AGREEMENT

     NOW, THEREFORE, for and in consideration of the covenants and agreements herein contained and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, Landlord and Tenant hereby agree, effective as of the Effective Date, as follows:

      1.  Premises . Landlord and Tenant hereby acknowledge and agree that the Premises consists of 61,211 rentable square feet and 57,549 useable square feet located on the forth, fifth and sixth floors of the Building.

      2.  Term . Section 1.6 of the Summary is hereby amended to provide for an Extended Term (the “Extended Term”) of an additional seventy two (72) months with the Extended Term commencing on February 1, 2007 and ending on January 31, 2013.

      3.  Monthly Basic Rent . Section 1.8 of the Summary is hereby amended to add the following schedule of Monthly Basic Rent

      4.  Base Year . Section 1.10 of the Summary is hereby amended to provide that during the Extension Period, the Base Year shall be the calendar year 2005.

      5.  Tenant Improvement Allowance . As of the Effective Date, and for a period of twelve (12) months following the first day of the first month thereafter, Tenant shall be entitled to a tenant changes allowance (the “Tenant Changes Allowance”) of up to TEN DOLLARS ($10.00) per useable square foot of the Premises for a total maximum Tenant Changes Allowance of Five Hundred Seventy Five Thousand Four Hundred Dollars ($575,400.00) for Tenant�