ATG Completes Acquisition of CleverSet

CAMBRIDGE, Mass.--(Business Wire)--
ATG (Art Technology Group, Inc., NASDAQ: ARTG), today announced
that it has completed its acquisition of CleverSet in a transaction
valued at approximately $9 million in cash.

On January 22, 2008, ATG announced a definitive agreement to
acquire privately held CleverSet, a technology leader in the rapidly
growing field of automated personalization engines, used to optimize
e-commerce experiences by presenting visitors with relevant
recommendations and information. CleverSet's next-generation
technology has been shown to significantly lift e-commerce revenue by
increasing conversion rates and order size.

The CleverSet offering expands ATG's eStara e-commerce
optimization services. These services - which include Click to Call,
Click to Chat, Call Tracking and now, automated personalization - are
delivered via a Software-as-a-Service (SaaS) model and can be easily
added to any Web site, whether built on the ATG platform or any other
Web technology.

ATG will retain both CleverSet offices, which are located in
Corvallis, Oregon and Seattle. Todd Humphrey, former CEO of CleverSet,
will assume the role of VP, OnDemand Personalization, reporting to
ATG's CEO, Bob Burke. CleverSet co-founder Bruce D'Ambrosio, Ph.D.,
will become VP and chief architect, OnDemand Personalization, and
report to Ken Volpe, ATG's SVP of products and technology. CleverSet's
other co-founder, Jane Jorgensen, Ph.D., has been named principal
scientist at ATG and will also report to Volpe. All other CleverSet
employees have also been offered positions with ATG.

"Personalization has always been a key part of ATG's market
leading commerce offerings. Now merchants can have the best of both
worlds: ATG's current rules- and scenario-based personalization when
they know what offers and information are best to present to their
different customer segments, and CleverSet's automated personalization
when they don't," said Burke. "With both of these technologies, we
believe we now have the most comprehensive personalization solution
that exists today."

Two Approaches to Personalization

-- The rules-based personalization in ATG's e-commerce platform
is the optimal choice for creating a dynamic site that tailors
itself to the needs of well-defined segments of customers -
for example, showing one set of images or product groups to
fashion-conscious shoppers and other images and products to
bargain shoppers. It gives merchants total control over offers
and allows them to apply their merchandising strategy to
search results.

-- CleverSet delivers automated personalized product
recommendations. Its patented technology "learns" what
recommendations are best. Since it is automated, merchants
need not be involved. It does not require knowledge of
customer segments or their behavior and takes minimal time to
initiate and manage. Because it is a SaaS offering, online
sellers can quickly and easily implement CleverSet alone or as
a complement to their existing personalization efforts.

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, Nokia,
NutriSystem, OfficeMax, PayPal, Philips, Procter & Gamble, Sears,
Sony, Symantec, Target, T-Mobile, Tommy Hilfiger, Urban Outfitters,
Verizon, Viacom, Vodafone and Walgreens.

This press release contains forward-looking statements about the
company's estimated revenue and earnings. 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. These risks include the effect of weakened
or weakening economic conditions or perceived conditions on the level
of spending by customers and prospective customers for ATG's software
and services; financial and other effects of cost control measures;
quarterly fluctuations in ATG's revenues or other operating results;
customization and deployment delays or errors associated with ATG's
products; the risk of longer sales cycles for ATG's products and ATG's
ability to conclude sales based on purchasing decisions that are
delayed; satisfaction levels of customers regarding the implementation
and performance of ATG's products; ATG's need to maintain, enhance,
and leverage business relationships with resellers and other parties
who may be affected by changes in the economic climate; ATG's ability
to attract and maintain qualified executives and other personnel and
to motivate employees; activities by ATG and others related to the
protection of intellectual property; potential adverse financial and
other effects of litigation (including intellectual property
infringement claims) and the release of competitive products and other
activities by competitors. Further details on these risks are set
forth in ATG's filings with the Securities and Exchange Commission
(SEC), including the company's annual report on Form 10-K for the
period ended December 31, 2006, and its quarterly report on Form 10-Q
for the period ended September 30, 2007, as filed with the SEC. These
filings are available free of charge on a website maintained by the
SEC at www.sec.gov.

For press:
ATG
Tucker Walsh, 617-386-1159
twalsh@atg.com
or
CleverSet
Donna Custance, 206-965-8737
donna@cleverset.com
or
Matter Communications
Matt Mendolera, 978-499-9250 x243
atg@matternow.com
or
For investors:
ATG
Kim Maxwell, 617-386-1006
kmaxwell@atg.com

Copyright Business Wire 2008