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

Market Wire, November, 2007

Data Domain, Inc. (NASDAQ: DDUP) has been named a Rising Star in Deloitte & Touche USA LLP's Technology Fast 50 program for Silicon Valley. Out of the 50 nominees for the award, Data Domain placed second in terms of revenue growth, with 5,861 percent revenue growth over the past three years.

The Rising Star award is a special designation for fast-growth companies that have been in business a minimum of three years, but less than five of revenue generation, and is part of the Silicon Valley Technology Fast 50 program, which ranks the 50 fastest growing technology, media, telecommunications, and life sciences companies headquartered in Silicon Valley. Rankings are based on percentage revenue growth over three years (2004-2006) for companies for which data is available. This year's Silicon Valley Technology Fast 50 program is co-presented by Deloitte & Touche USA LLP and Silicon Valley Bank, Cooley Godward Kronish LLP, Korn/Ferry International, and Woodruff-Sawyer & Co.

Data Domain® is a leading provider of Deduplication Storage systems for a broad range of nearline storage applications including disk backup, archiving and network-based disaster recovery. Data Domain has sustained fourteen consecutive quarters of growth since its first product was released in early 2004. Data Domain has sold its products to more than 1,200 enterprises worldwide, and across all industries, including the legal, financial, government, education, healthcare, manufacturing, pharmaceutical, technology and energy sectors.

"The Deloitte Silicon Valley Technology Fast 50 Rising Star companies have shown the strength, vision and tenacity to succeed despite a very challenging technology environment," said Mark Jensen, partner and national director, Venture Capital Services, Deloitte & Touche LLP. "We applaud the successes of Data Domain, Inc. and acknowledge its place as one of the few to accomplish such a fast growth rate over the past three years."

"This award underscores both the strength of our products and the focus on success that is typical of Data Domain's employees," said Frank Slootman, President and CEO of Data Domain. "The growth we've sustained since we first started shipping product back in early 2004 has made Data Domain an exciting journey for everyone at the company. We are honored to receive this award and grateful to the people at Deloitte & Touche for recognizing Data Domain's achievements."

ABOUT THE DELOITTE & TOUCHE FAST 50 RISING STAR PROGRAM

To qualify for the Technology Fast 50 Rising Star program, companies must be incorporated a minimum of three years and have revenues in only three or four years, have operating revenues of at least $50,000 in 2004 and $5,000,000 in 2006, be headquartered within the San Francisco Bay Area (subsidiaries or divisions are not eligible, unless they have some public ownership and are separately traded), and own proprietary technology or proprietary intellectual property that contributes to a significant portion of the company's operating revenues or devote a significant proportion of revenues to the research and development of technology. Using other companies' technology or intellectual property in a unique way does not qualify.

Rising Star companies are automatically entered in Deloitte's Technology Fast 500 Rising Star category. Deloitte's Technology Fast 500 program ranks North America's top 500 fastest growing technology, media, telecommunications, and life sciences companies based on percentage revenue growth over five years (2002-2006). Its Rising Star ranking is based on percentage revenue growth over three years (2004-2006) for companies for which data is available. For more information on Deloitte's Technology Fast 500 or Technology Fast 50 programs, visit www.fast500.com .

ABOUT DELOITTE

Deloitte refers to one or more of Deloitte Touche Tohmatsu, a Swiss Verein, its member firms and their respective subsidiaries and affiliates. As a Swiss Verein (association), neither Deloitte Touche Tohmatsu nor any of its member firms has any liability for each other's acts or omissions. Each of the member firms is a separate and independent legal entity operating under the names "Deloitte," "Deloitte & Touche," "Deloitte Touche Tohmatsu" or other related names. Services are provided by the member firms or their subsidiaries or affiliates and not by the Deloitte Touche Tohmatsu Verein.

Deloitte & Touche USA LLP is the US member firm of Deloitte Touche Tohmatsu. In the US, services are provided by the subsidiaries of Deloitte & Touche USA LLP (Deloitte & Touche LLP, Deloitte Consulting LLP, Deloitte Financial Advisory Services LLP, Deloitte Tax LLP and their subsidiaries), and not by Deloitte & Touche USA LLP.

ABOUT DATA DOMAIN

Data Domain® is a leading provider of Deduplication Storage systems for a broad range of nearline storage applications including disk backup, archiving and network-based disaster recovery. Over 1,200 companies worldwide have purchased Data Domain's storage systems to reduce costs and simplify data management. Data Domain delivers the performance, reliability and scalability to address the data protection needs of enterprises of all sizes. Data Domain's products integrate into existing customer infrastructures and are compatible with leading enterprise backup software products. To find out more about Data Domain, visit www.datadomain.com . Data Domain is headquartered at 2300 Central Expressway, Santa Clara, CA 95050 and can be contacted by phone at 1-866-933-3873 or by e-mail at sales@datadomain.com .