AMENDMENT TO RIGHTS AGREEMENT

Exhibit 4.1

AMENDMENT TO RIGHTS AGREEMENT

This Amendment to Rights Agreement (this “Amendment”), dated as of May 29, 2008, between Kintera, Inc., a Delaware corporation (the “Company”), and Computershare (formerly U.S. Stock Transfer Corporation), as Rights Agent (the “Rights Agent”), amends that certain Rights Agreement, dated as of January 25, 2006, by and between the Company and the Rights Agent (the “Rights Agreement”).

WHEREAS, the Company and the Rights Agent have heretofore executed and entered into the Rights Agreement;

WHEREAS, pursuant to Section 26 of the Rights Agreement, the Company may, and the Rights Agent shall if the Company so directs, from time to time supplement or amend any provision of the Rights Agreement, under certain circumstances; and

WHEREAS, all acts and things necessary to make this Amendment a valid agreement according to its terms have been done and performed, and the execution and delivery of this Amendment by the Company and the Rights Agent have been in all respects authorized by the Company.

In consideration of the foregoing and mutual agreements set forth in the Rights Agreement and this Amendment, the parties hereto agree as follows:

“and; (H) Blackbaud, Inc., a Delaware corporation (“Blackbaud”), or any Affiliate thereof, including Eucalyptus Acquisition Corporation, a Delaware corporation and wholly-owned subsidiary of Blackbaud (“Merger Sub”), shall not become an “Acquiring Person” as a result of (i) the approval, execution or delivery of that certain Agreement and Plan of Merger, dated as of May 29, 2008, by and among the Company, Blackbaud and Merger Sub (as the same may be amended from time to time, the “Merger Agreement”), including the approval, execution and delivery of any amendments thereto, (ii) the consummation of the Offer or the Merger pursuant to, and as defined in, the Merger Agreement, (iii) the acceptance for payment and purchase or tender of Company Shares pursuant to the Merger Agreement, (iv) the announcement of the Merger Agreement, the Offer or the Merger, or (v) the consummation of any other transaction contemplated by the Merger Agreement.”

“Each Person identified in subclauses (A), (B), (C), (D), (E), (F), (G) and (H) of this Section 1(a)(i) is individually an “Exempt Person” and collectively “Exempt Persons.”

“For purposes of clarity, notwithstanding anything in this Agreement to the contrary, this Section 11(a)(ii) shall not be deemed to apply to, and a Section 11(a)(ii) Event shall not have occurred with respect to, any of the following: (i) the approval, execution or delivery of the Merger Agreement, including the approval, execution and delivery of the amendments thereto, (ii) the consummation of the Offer or the Merger pursuant to, and as defined in, the Merger Agreement, (iii) the acceptance for payment and purchase or tender of Shares pursuant to the Merger Agreement, (iv) the announcement of the Merger Agreement, the Offer or the Merger, or (v) the consummation of any other transaction contemplated by the Merger Agreement.”

“For purposes of clarity, notwithstanding anything in this Agreement to the contrary, none of the events described in clauses (x) through (z) of the first sentence of this Section 13(a) shall be deemed to have occurred solely as a result of, and a Section 13 Event shall not be deemed to have occurred in connection with, (i) the approval, execution or delivery of the Merger Agreement, including the approval, execution and delivery of any amendments thereto, (ii) the consummation of the Offer or the Merger pursuant to, and as defined in, the Merger Agreement, (iii) the acceptance for payment and purchase or tender of Shares pursuant to the Merger Agreement, (iv) the announcement of the Merger Agreement, the Offer or the Merger, or (v) the consummation of any other transaction contemplated by the Merger Agreement.”

IN WITNESS WHEREOF, the parties hereto have caused this Amendment to Rights Agreement to be duly executed as of the day and year first above written.