PRESS RELEASE DETAIL


Dec 21, 2007

CoStar Group Signs Marcus & Millichap to Multi-Year Renewal

2005-02-15 2005 CoStar Group Signs Marcus & Millichap to Multi-Year Renewal Nation's Largest Investment Sales Brokerage Firm Expands Users, Sites Under Multi-Marke...

2005-02-15 2005 CoStar Group Signs Marcus & Millichap to Multi-Year Renewal Nation's Largest Investment Sales Brokerage Firm Expands Users, Sites Under Multi-Market License Agreement

BETHESDA, MD -- CoStar Group, Inc. (NASDAQ: CSGP) today announced it has signed a multi-year, multi-market renewal agreement to provide comprehensive commercial real estate leasing and sales information to Marcus & Millichap, the nation's largest commercial real estate investment sales brokerage firm.

Marcus & Millichap has been a CoStar customer since 1983, and now has over 1,350 professionals accessing CoStar COMPS® and hundreds of professionals accessing CoStar Property® at 48 sites across the United States. Since 1995, the investment sales leader has opened 17 new offices and increased its brokerage force by over 40%. In 2004, the firm closed $14.4 billion in investment transactions nationally, up 40% over 2003. Marcus & Millichap is the largest consumer of CoStar COMPS, the industry's largest national database of verified commercial sale comparables.

"We are pleased to continue our association with one of the premier firms in the investment sales arena," stated CoStar Group President & CEO Andrew C. Florance. "When you consider that retail properties represent over 20% of all commercial sales transactions, we believe our major planned expansion into the retail real estate sector will make our services even more valuable to firms like Marcus & Millichap."

"Providing a comprehensive set of property and market analysis tools has been a pivotal part of helping our clients evaluate and form their investment strategies throughout our 34-year history," stated Marcus & Millichap President & CEO Harvey Green. "The information provided by CoStar is an important complement to the market data that we gather, analyze and interpret locally and nationally, and CoStar has been a strong and reliable information partner."

About CoStar Group, Inc.

CoStar Group, Inc., (NASDAQ: CSGP) is the leading provider of information services to commercial real estate professionals in the United States and the United Kingdom. CoStar's suite of services offers customers access via the Internet to the most comprehensive database of commercial real estate information on over 50 U.S. markets, London and the United Kingdom. Based in Bethesda, MD, the company has approximately 1,000 employees throughout the United States and the United Kingdom, including the largest professional research organization in the industry.

About Marcus & Millichap

With 38 offices nationwide and sales in excess of $10.3 billion in 2004, Encino, Calif.-based Marcus & Millichap is the largest commercial real estate brokerage in the nation focusing exclusively on real estate investments. Since its inception in 1971, the firm has perfected a powerful system for marketing properties that combines product specialization; local market expertise; the industry's most comprehensive research and analysis capabilities; state-of-the-art technology; and established relationships with the largest pool of qualified investors nationally.

This news release includes "forward-looking statements" including, without limitation, statements regarding CoStar's expectations, beliefs, intentions or strategies regarding the future. These statements are subject to many risks and uncertainties that could cause actual results to differ materially from these statements. More information about potential factors that could cause actual results to differ materially from those discussed in the forward-looking statements include, but are not limited to, those stated in CoStar's filings from time to time with the Securities and Exchange Commission, including CoStar's Form 10-Q for the quarter ended September 30, 2004, under the heading "Risk Factors." In addition to these statements, there can be no assurance that CoStar's planned expansion into the retail real estate sector will make its services more valuable. All forward-looking statements are based on information available to CoStar on the date hereof, and CoStar assumes no obligation to update such statements.
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