LoopNet 10-Q 2008 Q4 Quarterly report

Exhibit 32.1

Form of Section 1350 Certification (CEO)

LOOPNET, INC.

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of LoopNet, Inc. (the “Company”) on Form 10-Q for the quarter ended March 31, 2008, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Richard J. Boyle, Jr., Chief Executive Officer and Chairman of the Board of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1)	The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and
(2)	The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Richard J. Boyle, Jr.  

Richard J. Boyle, Jr. 

Chief Executive Officer and Chairman of the Board 

May 9, 2008

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