Data Domain, Inc. Named Rising Star in Deloitte's Technology Fast 50 Program for Silicon Valley

Market Wire, November, 2007

FORWARD-LOOKING STATEMENTS

This press release contains forward-looking statements that involve risks and uncertainties, as well as assumptions that, if they do not fully materialize or if they prove incorrect, could cause our results to differ materially from those expressed or implied by such forward-looking statements. Such forward-looking statements include statements regarding our expectations, beliefs, intentions or strategies regarding the future, such as statements regarding our products' ability to reduce the amount of stored back-up data and associated storage costs and simplify data management and to provide faster access to data and advanced levels of data protection; and other statements that can be identified by forward-looking words such as "anticipated," "believed," "could," "estimate," "expect," "intend," "may," "should," "will" and "would" or similar words. The risks and uncertainties that could cause our results to differ materially from those expressed or implied by such forward-looking statements include our ability to react to trends and challenges in our business and the markets in which we operate; our ability to anticipate market needs or develop new or enhanced products to meet those needs; market acceptance of our products; our ability to scale our distribution channels; our ability to compete in our industry; our ability to maintain and expand relationships with technology partners; our ability to recruit and retain qualified personnel and manage our growth; our ability to maintain effective internal controls; our dependence on a single product line; our ability to protect our intellectual property; claims by others that we may infringe their intellectual property; our dependence on sole or limited source suppliers; the ability of our contract manufacturer to perform as we expect; general political, economic and market conditions and events; and other risks and uncertainties described more fully in our documents filed with or furnished to the Securities and Exchange Commission. All forward-looking statements in this press release are based on information available to us as of the date hereof, and we assume no obligation to update these forward-looking statements.

Note: Data Domain, the Data Domain logo and Global Compression are trademarks or registered trademarks of Data Domain, Inc. All other trademarks used or mentioned herein belong to their respective owners.

Terry Frechette Lois Paul & Partners 1.781.782.5791 tfrechette@lpp.com Ed Luboja Data Domain, Inc. 1.914.698.1346 edward.luboja@datadomain.com