ATG COMMERCE BRINGS HARMONY TO MARS MUSIC`S ONLINE INITIATIVES

ATG Commerce and Scenario Personalization Help Drive In-Store Retail Strategies and Increase Online Sales

CAMBRIDGE, Mass., September 5, 2002 - ATG (Art Technology Group, Inc., Nasdaq: ARTG), a leading developer of online CRM applications for commerce, portals, and relationship management, today announced that Mars Music is using ATG Commerce and ATG Scenario Personalization(tm) to better serve and strengthen relationships with its community of musicians. Using ATG, Mars Music is now able to carry out consistent and complimentary campaigns across business channels, helping to ensure brand consistency and driving up cross-channel revenues.

The personalized experience customers enjoy at Mars Music`s online and Mars Music Superstores have made it the "music makers` destination," where musicians visit and shop for instruments, DJ, recording equipment, and pro audio gear to match their musical preferences and budgets. ATG Scenario Personalization is helping Mars Music translate that experience to the Web.

"We have always offered our full assortment of products in both the retail stores and the online store, but were not always able to offer the same promotions," said Christine Chalovich, vice president marketing for Mars Music. "Since re-launching our site with ATG, we are able to support our Bricks and Clicks strategy much more effectively. We are able to offer the same great deals on line with Scenario Personalization and react much more quickly to promotional opportunities that ensure our customers get the best deals and we realize our revenue potential."

Using ATG Commerce, the new site is helping the company to grow its national presence, particularly in markets not currently serviced by a Mars Music Superstore. The site also serves as a resource for customers to research gear and prices before going to a store location to make a final purchase. In fact, the company recognizes that 40 percent of the company`s Web traffic is derived from retail-only customers researching gear with the intent to buy in-store.

ATG Scenario Personalization capabilities enabled Mars Music to capture customer attributes and visitor behavior. By monitoring both online and offline shopping behavior and personal attributes, Mars Music can mirror the success promotional strategies across channels for each customer. For example, in-store promotions that offer packaged deals to guitar enthusiasts also can run on the Web for customers indicating guitar as a personal interest. These capabilities offer another means for the customer to save on merchandise related to his or her interests and Mars Music a way to maximize sales per customer.

"We are now positioned to customize the content, products and promotions based on looking across the entire customer profile including what they have bought in the past and what they are shopping for today," added Chalovich.

Hundreds of complex and personalized promotional events can be run simultaneously, ensuring that all customers get the best and most appropriate deals possible. With ATG, online promotions can be accurately tracked for traffic, conversion rate, and cost of the discounts, enabling Mars Music to easily evaluate return on investment and adjust campaigns to maximize the return. Fortunately, ATG enables these campaigns to be developed and modified by business users instead of developers, saving time and cost of executing campaigns.

"Acquiring and retaining consumers with personalized information based on their interests and their actions builds loyalty and profits," said Victor Cheng, senior director of ATG Commerce. "Mars Music exemplifies how online CRM and scenario-based personalization can enrich consumers` Web experience and drive sales at the same time."

About ATG

ATG (Art Technology Group, Inc.) is a leading developer of online CRM applications that deliver an integrated, personalized experience for customers, partners and employees: the frontline of every business. Customers around the globe rely on ATG for the frontline applications that help build and manage mutually beneficial relationships. Deployed on the industry`s most popular application servers, ATG solutions for commerce, portals, and relationship management are ideal for integrated e-business initiatives across the enterprise.

Today, ATG has delivered solutions to blue-chip companies worldwide, including Aetna Services, Inc., Alcatel, American Airlines, AT&T;, Barclays Global Investors, Best Buy, BMG Direct, Eastman Kodak, Ford Motor Credit, HSBC, J. Crew, Sun Microsystems, Walgreen Company, and WellsFargo and government organizations including the United States Army and the USDA. The company is headquartered in Cambridge, Massachusetts, with additional locations throughout North America, Europe, and Asia. For more information about ATG, please visit our Web site at www.atg.com .

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* 2002. ATG and Art Technology Group are registered trademarks of Art Technology Group, Inc. Scenario Personalization is a service mark of ATG. 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 ATG`s periodic reports and registration statements filed with the Securities and Exchange Commission. Risk factors related to the subject matter of this press release include the possibility that the ATG product deployment will not be successful or significantly enhance the user`s internet experience or handle user volumes, 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 and more flexible; 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.