Vodafone Selects ATG for Email Response Management; World's Largest Mobile Telecommunications Company Chooses Wisdom-Enabled ATG; Response Management to Manage Email and Web Customer Communication.

CAMBRIDGE, Mass. -- ATG (Art Technology Group, Inc., NASDAQ: ARTG) the software provider behind the most consistent and relevant marketing, commerce, and customer service experiences, today announced that Vodafone Espana, a subsidiary of the world's largest mobile telecommunications company, has selected ATG Response Management to make email and web communications with customers more responsive, efficient, and cost-effective.

"More and more consumers are choosing to communicate with their suppliers via email, web forms and mobile messaging," said Cliff Conneighton, senior vice president of marketing, ATG. "This is beneficial for the companies, because it reduces expensive calls to agents in contact centers, which typically cost at least three times more to handle. But as the volume increases, companies find they must deploy email response management systems (ERMS) to ensure efficient and timely response. Forward-looking companies, such as Vodafone, are moving rapidly in this direction and ATG is providing the solutions to help them best achieve those goals."

ATG Response Management is a comprehensive solution, empowering companies to meet customers' growing desire to communicate with companies on their own terms, via email, Web forms, and mobile messaging. By integrating all of these forms of communication, ATG Response Management helps companies offer more responsive, satisfying, and cost-effective customer service, while gaining significant savings in support costs. Moreover, ATG Response Management can be used as part of the Wisdom-enabled ATG Service Suite, to ensure the continuity of customers' experience regardless of whether they interact with a company via telephone, e-mail, Web forms, or Web self-service. ATG Response Management is available as traditional licensed software or as a managed service.

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 service lifecycle, and across the Web, e-mail, call center, and mobile channels. Offering an alternative to the traditional silo-based approach to customer-facing applications, ATG Wisdom(TM) is the company's strategy for delivering a seamless, more compelling, and mutually valuable experience to each customer and segment. The company fulfills this strategy by providing fully integrated best-of-breed product suites installed on-premise or delivered on-demand. ATG's solutions power over 600 major brands, including A&E Networks, Airbus, American Airlines, American Eagle Outfitters, Best Buy, Boeing, Cingular Wireless, DirecTV, France Telecom, Friends Provident, Hewlett-Packard, Hotels.com, Hyatt Hotels, HSBC, InterContinental Hotels Group, Kingfisher, Louis Vuitton, Merrill Lynch, Neiman Marcus, Philips, Procter & Gamble, Symantec, T-Mobile, Target, USAA, US Army, US Navy, Warner Music, and Wells Fargo. The company is headquartered in Cambridge, Massachusetts, with additional locations throughout North America, Europe, and Asia. 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 won't 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.