ATG Insight Live 2008 Draws More Than 650 e-Commerce Revolutionaries

Business Wire, April 28, 2008

Attendance Hits New Record at ATG's Annual User Conference, Bringing Together Industry Experts and Authorities from the World's Largest Brands

CAMBRIDGE, Mass. -- ATG (Art Technology Group, Inc., NASDAQ: ARTG), the leading e-commerce platform and optimization services provider, today announced record-breaking attendance of more than 650 participants at Insight Live 2008, the company's annual user conference. Attendees gathered include industry analysts and experts from businesses that are revolutionizing the e-commerce industry with their work for the largest and most innovative brands in retail, consumer product manufacturing, telecommunications, media and entertainment, and financial services.

Spotlighting the theme "The Commerce Revolution," Insight Live 2008 gives companies using ATG's e-commerce software suite and eStara e-commerce optimization services a chance to share their experiences and learn from well-respected thought leaders and experts, as well as discuss their likely future e-commerce priorities in a new series of "Futures Forums." During these sessions, attendees meet managers and strategists leading ATG's product evolution decisions to discuss how their future priorities can intersect with the direction of potential new ATG and eStara developments.

"Insight Live is an enlightening and rewarding event not just for our customers and partners, but for ATG as well," said Cliff Conneighton, senior vice president of marketing, ATG. "Every year we learn new and exciting ways that this diverse crowd of global brands is using ATG technology to shape the way they sell to, and interact with their customers. This kind of dialog is both refreshing and inspiring, and often times informs the direction we take in developing cutting-edge products that resolve challenges online sellers face today. Further, attendees are able to connect and exchange ideas, ultimately affording our customers the ability to maximize the power of their ATG applications. The conference is already off to a great start with our biggest audience ever."

Insight Live attendees will also witness the presentations and award ceremony for the first ATG e-Commerce Ingenuity Business Plan Competition - and they will have an opportunity to affect the outcome, by selecting a "People's Choice" winner who will receive a monetary prize.

To find more information on ATG Insight Live 2008, please visit: http://www.atg.com/insightlive2008/

About ATG

ATG (Art Technology Group, Inc., NASDAQ: ARTG) provides the e-commerce platform and e-commerce optimization services that the world's most customer-conscious companies use to power their e-commerce Web sites, attract prospects, convert them to buyers and ensure their satisfaction so they become loyal, repeat, profitable customers. Our e-commerce suite is ranked the #1 current offering and #1 in strategy by the industry's most influential analyst firms, and powers more of the top 300 internet retailers than any other vendor. Our eStara brand of e-commerce optimization services - including the world's most widely used click to call offering - dramatically increase conversions and order size and enhance customer support. ATG's solutions are used by over 900 major brands, including AT&T, Best Buy, Bulgari, Coca Cola, Continental Airlines, CVS, Dell, Diane von Furstenberg, DirecTV, eLuxury, El Corte Ingles, Expedia, France Telecom, Harvard Business School Publishing, Hewlett-Packard, Hilton, HSBC, Intuit, Jenny Craig, Louis Vuitton, Macy's, Mercedes Benz, Meredith, Microsoft, Neiman Marcus, New York & Company, NutriSystem, OfficeMax, PayPal, Philips, Procter & Gamble, Sears, Sony, Symantec, Target, T-Mobile, Tommy Hilfiger, Urban Outfitters, Verizon, Viacom, Vodafone and Walgreens.

(c) 2008 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.