ATG (Art Technology Group, Inc., NASDAQ: ARTG) delivers innovative software to help high-end consumer-facing companies create a richer, more adaptive interactive experience for their customers and partners online and via other channels. ATG has delivered category-leading e-business solutions to many of the world's best-known brands including A&E Television, Aetna Services, Inc., Alcatel, American Airlines, Barclays Global Investors, Best Buy, BMG Direct, Eastman Kodak, Ford Motor Credit, HSBC, Hyatt, J.Crew, Merrill Lynch, Newell Rubbermaid, Target, U.S. Army, Walgreen Company 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.

ATG Honored for its Customer Experience Platform

CAMBRIDGE, Mass. - July 20, 2005 - ATG (Art Technology Group, NASDAQ: ARTG), the software provider behind the most consistent and relevant marketing, commerce, and customer service experiences, today announced that it has received the 2005 CRM Excellence Award from Customer Interaction Solutions magazine, the leading publication in CRM, call centers and teleservices since 1982?. ATG's Customer Experience Platform was awarded for its ability to drive ROI for the hundreds of top brands that use the technology.

Once a year, the CRM Excellence awards are presented to companies that provide stories of CRM success experienced by their clients after implementing their company's CRM software or services. Awards are based on hard data numbers demonstrating the improvements that the winner's product has made in one of its client's businesses.

"Customer Interaction Solutions magazine implemented the CRM Excellence Awards six years ago as a way of commending the companies that have proven to be true CRM partners to their customers and clients. ATG has demonstrated to the editors of Customer Interaction Solutions that their products and services have substantially improved the processes of their clients' businesses by streamlining and facilitating the flow of information needed for companies to retain their most precious asset...their customers," said Nadji Tehrani, founder and chairman of TMC, publishers of Customer Interaction Solutions.

ATG Customer Experience Platform includes the ATG Adaptive Scenario Engine (ASE), ATG's core marketing engine, which provides the foundation companies need to create a more relevant and compelling customer experience - resulting in higher revenue, greater customer loyalty, and reduced operating costs. By helping customers learn about, adapt to, and respond to customers' ever changing needs and preferences, ASE automates the process of leading customers toward a desired outcome (such as making a purchase, fulfilling a service need, or accessing information). Companies such as Merrill Lynch, Newell Rubbermaid, Hyatt Corporation, American Airlines, and A&E Television Networks utilize the Adaptive Scenario Engine to deliver compelling, relevant, and mutually rewarding customer experiences.

"ATG constantly strives to help companies provide a more satisfying customer experience, in a way that is much easier to develop, and more focused on customers, than solutions others offer. We are honored to receive this award," said Cliff Conneighton, senior vice president of marketing, ATG. "Our ability to drive rich customer segmentation, profiling, and targeting across the customer lifecycle provides a more personal, rich, and rewarding experience."

About ATG

ATG (Art Technology Group, Inc., NASDAQ: ARTG) makes the software that the world's largest and most prestigious companies use to create a relevant and consistent customer experience, across the Web, e-mail, call center, and mobile channels; and throughout the marketing, commerce, and service lifecycle. With ATG, world-class enterprises create and manage highly targeted online commerce and marketing campaigns, as well as loyalty-driving and cost effective knowledge management, customer service, and support initiatives. ATG's solutions power brands including A&E Networks, Airbus, American Airlines, American Eagle Outfitters, AT&T Wireless, Best Buy, Boeing, France Telecom, Friends Provident, General Electric, Hewlett-Packard, HSBC, InterContinental Hotels Group, Kingfisher, Merrill Lynch, Neiman Marcus, Philips, Procter & Gamble, SBC, T-Mobile, Target, US Army, US Federal Aviation Administration, Warner Music, Wells Fargo, and Yahoo! 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.

? 2005 Art Technology Group, Inc. ATG and Art Technology Group are registered trademarks 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 their 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 handle user volumes; 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 customer will not close additional business due to the implementation of the ATG product; 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.