Ziff Davis (ZD) 10-Q 2009 Q2 Quarterly report

Exhibit 32.1

CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER

PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Nehemia Zucker, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that:

1. The accompanying quarterly report on Form 10-Q for the quarter ended June 30, 2009 (the “Report”) fully complies with the requirements of Section 13(a) or 15(d), as applicable, of the Securities and Exchange Act of 1934, as amended; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of j2 Global Communications, Inc.

Dated: August 5, 2009 /s/ NEHEMIA ZUCKER Nehemia Zucker Chief Executive Officer (Principal Executive Officer)

A signed original of this written statement required by Section 906 of the Sarbanes-Oxley Act has been provided to j2 Global Communications, Inc. and will be retained by j2 Global Communications, Inc. and furnished to the Securities and Exchange Commission or its staff upon request.