PRESS RELEASE DETAIL


Dec 27, 2007

CoStar Group Continues Nationwide Expansion

1999-12-21 1999 CoStar Group Continues Nationwide Expansion Charlotte, Cincinnati, Cleveland, Columbus, St. Louis and Seattle Property Data Added to CoStar's Standardi...

1999-12-21 1999 CoStar Group Continues Nationwide Expansion Charlotte, Cincinnati, Cleveland, Columbus, St. Louis and Seattle Property Data Added to CoStar's Standardized Commercial Real Estate Database

BETHESDA, MD -- CoStar Group, Inc. (Nasdaq: CSGP), http://www.costargroup.com, a leading business-to-business provider of information services to the U.S. commercial real estate industry, today announced that it added comprehensive property data in six major metropolitan markets covering more than 1.6 billion square feet of office and industrial property to its standardized CoStar Property™ commercial real estate database. The addition results in a significant increase in the amount of office and industrial space tracked by CoStar, and in the number of markets in which the Company has released its CoStar Property™ and CoStar Tenant™ software.

Five of the six markets were added as the result of the successful conversion of property and tenant databases obtained from LeaseTrend, Inc., encompassing the Charlotte, Cincinnati, Cleveland, Columbus and St. Louis metropolitan areas. This conversion effort follows CoStar Group's acquisition earlier this year of LeaseTrend, a Cincinnati-based real estate information provider with operations in 18 markets across the country. In addition, CoStar added the Seattle market as a completely new addition, with comprehensive office and industrial property compiled by CoStar's research staff.

Following the successful conversion and the release of CoStar Property™ in the above markets, the Company recorded strong upgrade sales and a 57% increase in the contract revenue base in those regions.

CoStar's research staff updated the information and made a concerted effort to inventory additional buildings that were not included in the purchased LeaseTrend database. These efforts accounted for more than 4,000 additional buildings containing approximately 695 million square feet of office and industrial space, significantly expanding LeaseTrend's original database.

The Company announced it also released its CoStar Tenant™ product in the former LeaseTrend markets, profiling more than 52,000 tenants currently occupying space in the Charlotte, Cincinnati, Cleveland, Columbus and St. Louis regions. Subscribers can use this product to look up information about particular clients, identify and target the most likely tenants to lease space and determine the underlying demand for commercial real estate in their area.

Additionally, the Company announced it added comprehensive property data encompassing office and industrial properties in metropolitan Seattle to its CoStar Property™ database. With this addition, Seattle subscribers to CoStar Property™ now have access to comprehensive property data on approximately 6,500 office and industrial buildings throughout the region comprising more than 342 million square feet.

"Prior to CoStar, access to comprehensive commercial property data involved a patchwork of fragmented and regionalized providers using different measurement and data standards," stated Andrew C. Florance, President and CEO of CoStar Group. "By offering a truly national, high-quality, standardized commercial property database we are bringing order and offering value to investors and real estate practitioners alike."

"As we grow, we will continue serving our clients by providing more time-saving, comprehensive and accurate information products that will help establish and support a digital commercial real estate marketplace," added Florance, referring to the merger agreement announced last month between CoStar Group and COMPS.COM (Nasdaq: CDOT), a national provider of comparable building sale information and other commercial real estate information services. It is expected that the combination of the two companies will create the largest provider of comprehensive commercial real estate information and transaction support services in the United States. The merger is expected to close in the first half of 2000.

About CoStar

Headquartered in Bethesda, MD, CoStar Group, Inc., is a leading provider of information services to the U.S. commercial real estate industry. An estimated 25,000 end-users use CoStar's Internet-delivered database, CoStar Property™, to track approximately 326,000 buildings in 41 markets totaling more than 15.3 billion square feet. Approximately 370,000 tenants are listed in CoStar's state-of-the-art software package, CoStar Tenant™.

This news release includes certain "forward-looking statements," which involve many risks and uncertainties that could cause actual results to differ materially from such statements. Important factors that could cause actual results to differ materially include but are not limited to those listed in CoStar's Registration Statement on Form S-1, as amended, filed March 24, 1999.
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