ATG Powers Commerce Sites Rated Highest for Online Shopping Experience.

More Sites in the Top 300 Named by Internet Retailer Run on ATG Than Any Other Vendor; Two ATG Customers Hold Top Spots in Both Benchmark Study and RIS Fusion Awards for Customer Experience

CAMBRIDGE, Mass. -- ATG (Art Technology Group, Inc., NASDAQ: ARTG), the leading eCommerce platform provider, today announced that ATG powers the highest number of retail sites among the top 300 ranked by Internet Retailer magazine. Additionally, two ATG Commerce customers have achieved further distinction, noted for offering the best shopping experience among 20 major U.S. retail sites, according to a study released by Cisco System's Internet Business Solutions Group (IBSG), and also named the winners in the 2006 RIS Fusion Awards for customer experience.

Internet Retailer 's annual "Top 500 Guide" features ATG-powered retail sites including OfficeMax, Best Buy, Neiman Marcus Group, Footlocker, Peapod, Cabela's, J.Crew, Walgreens, The Sharper Image, American Eagle Outfitters, Sephora, The Finish Line, Urban Outfitters, Road Runner Sports, Franklin Covey, Nike, Joann.com, Casual Male, eLuxury, A&E TV, Restoration Hardware, and many more. These companies rely on ATG's platform as the technology sustaining their substantial web retailing operations. Now in its third year, the list is considered the definitive ranking and analysis of America's 500 largest e-retailers based on their annual sales on the web.

Both Cabelas.com and Best Buy were recognized individually by Cisco IBSG for their successes with ATG Commerce. The benchmark, focusing on new trends in online shopping sites, rates Cabelas.com, the foremost outfitter for hunters and fishermen, as the "clear leader" in online shopping experiences with Best Buy, a Fortune 100 consumer electronics retailer, rating second-highest. Cisco IBSG evaluated each retail website and purchased items on each site to compare back-end processes of these businesses from an "outside in" perspective to measure the buyer's experience throughout the entire shopping lifecycle.

RIS (Retail Information Systems), also named Cabelas.com and Best Buy the two winners for customer experience in their annual "Fusion Awards for Excellence in Retail Management." The retailers were cited for offering customer-centric and superior customer shopping experiences.

"These recent honors confirm ATG's leadership position as the most popular e-commerce platform," said Cliff Conneighton, senior vice president of marketing at ATG. "ATG Commerce puts control in the hands of the merchandisers, enabling them to create a more personalized, more relevant shopping experience, which in turn drives up conversion rates and makes sites more successful. As internet commerce continues to grow, more and more companies will demand this kind of functionality, and that's why we've brought it to our hosted, software-as-a-service offer, ATG OnDemand. ATG congratulates both Cabelas.com and Best Buy for receiving these special accolades, and we are proud to have helped each of our customers in the IR500 build a successful online presence."

In September, ATG Commerce was ranked number one among current business to consumer e-commerce offerings by Forrester Research and earlier this year, ATG announced major enhancements to its top-rated e-Commerce Platform with new features including "Searchandising," dynamic navigation capabilities, Live Chat, and advanced Customer Intelligence capabilities. These upgrades further solidified ATG's position as the industry standard for serious e-commerce solutions, providing a multi-channel, multi-touch, guided experience throughout the entire marketing, sales, and customer care lifecycle.

About ATG

ATG (Art Technology Group, Inc., NASDAQ: ARTG) makes the software that the world's most customer-conscious companies use to create a more relevant and consistent customer experience, throughout the marketing, commerce, and customer care lifecycle, and across the Web, e-mail, chat, call center, and mobile channels. Offering an alternative to the traditional silo-based approach to customer-facing applications, the ATG Wisdom[TM] platform integrates ATG's best of breed products into a seamless, more compelling experience made relevant to each customer and segment through unique content targeting technology. ATG solutions are available through traditional licensing or delivered as a service, on-demand. ATG's solutions power over 600 major brands, including Adobe, A&E Networks, American Eagle Outfitters, B&Q, Best Buy, Cingular Wireless, Dell, DirecTV, France Telecom, Hewlett-Packard, Intuit, Johnson & Johnson, Louis Vuitton, Mercedes-Benz, Neiman Marcus, New York & Company, Nokia, Nike, OfficeMax, PayPal, Philips, Procter & Gamble, Rubbermaid, Smith & Hawken, Symantec, T-Mobile, Target, Verisign, and Walgreens. The company is headquartered in Cambridge, Massachusetts, with additional locations throughout North America and Europe. For more information about ATG, please visit www.atg.com.

[c] 2006 Art Technology Group, Inc. ATG and Art Technology Group are registered trademarks, and ATG Wisdom is a trademark of Art Technology Group, Inc. All other product names, service marks, and trademarks mentioned herein are trademarks of their respective owners.

This press release contains forward-looking statements for purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995. These statements involve known and unknown risks and uncertainties that may cause ATG's actual results, levels of activity, performance or achievements to be materially different from any future results, levels of activity, performance or achievements expressed or implied by such forward-looking statements. Important risk factors affecting ATG's business generally may be found in its periodic reports and registration statements filed with the Securities and Exchange Commission at www.sec.gov . Risk factors related to the subject matter of this press release include the possibility that the ATG product deployment will not be successful, on time or significantly enhance the user's Internet experience or will not increase customer revenue across brands; that those customers leveraging ATG will not have the opportunity to increase revenue and decrease future costs; the need to adapt to rapid changes so products do not become obsolete; the possibility of errors in ATG's software products; the possibility that the solution will not make customer implementations faster or more flexible or permit the customer to meet its customer-facing or infrastructure requirements; that the ATG product will not continue to be integrated with third party applications servers or will not support all Web services enabled systems; that ATG's product strategy may change in the future; and the risks and costs of intellectual property litigation. ATG undertakes no obligation to update any of the forward-looking statements after the date of this press release.