ATG to Acquire Automated Personalization and Recommendations Leader CleverSet

CAMBRIDGE, Mass. & SEATTLE--(Business Wire)--ATG (Art Technology Group, Inc., NASDAQ: ARTG), and CleverSet
today announced that the two companies signed a definitive agreement
for ATG to acquire CleverSet for approximately $10 million in cash,
less closing adjustments of approximately $1 million. The transaction
is subject to customary closing conditions, including the approval of
CleverSet's stockholders, and is expected to occur in the current
quarter. The transaction is expected to be accretive on a non-GAAP
diluted per share basis in 2009.

CleverSet is 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.

According to CleverSet's founder, Dr. Bruce D'Ambrosio, associate
professor emeritus at Oregon State University, "CleverSet's patented
technology incorporates advanced statistical relational learning,
based on Bayesian network analysis, originally developed by CleverSet
for the US Department of Defense and other government agencies for
applications in e-commerce, intelligence analysis and other real-time
applications." This approach drives more relevant experiences for
online customers by using more types of data from more sources,
compared to techniques like collaborative filtering. CleverSet's
personalization engine incorporates billions of data points such as
real-time and historical onsite behavior, other shoppers' behavior,
buying history, catalog information, merchandising strategy and
external conditions - such as time of day, day of week and seasonality
- to deliver more relevant recommendations.

In 2007, CleverSet was awarded "Best in Show" at the Web 2.0
Summit and named "America's Most Innovative Company" by the American
Business Association. The company has benefited from leadership with a
diverse set of experience and expertise critical to developing a
successful emerging technology. CleverSet's executives and advisors
are comprised of individuals from top academic institutions, venture
capital firms and influential Internet companies, such as Google,
Amazon and eBay.

By complementing ATG's robust, merchant-driven, scenario-based
personalization already employed by the company's commerce platform
customers, CleverSet will advance ATG's mission of enabling online
sellers to find customers, convert them into buyers and ensure their
satisfaction with the goal of developing a loyal and profitable
customer base. CleverSet's automated personalization and
recommendations engine is applicable across a wide-range of industries
like retail, manufacturing, telecommunications, financial services,
travel and hospitality and more. Delivered via a SaaS model, CleverSet
can be easily added to any Web site. Once installed, CleverSet
"learns" how to deliver more relevant, personalized offers and drive
cross-sell and up-sell recommendations. CleverSet does not require
day-to-day involvement of the merchant's business or IT staff.

"This acquisition will enable us to help online sellers across
multiple industries optimize their e-commerce investments and provide
the best shopping experience for their customers." said Bob Burke, ATG
president and CEO. "CleverSet's market-leading automated
personalization technology is an ideal on demand solution that
complements rules-based personalization already built into ATG's core
commerce platform."

"CleverSet has proven that our superior technology delivers
superior results," said CleverSet CEO, Todd Humphrey. "Coupling that
with ATG's reputation as the e-commerce leader and its established
sales, marketing and partner network will enable the CleverSet
technology to reach its full potential."

The Growing Importance of Personalization

ATG's acquisition of CleverSet comes an opportune time, as
optimized e-commerce through enhanced personalization is fast becoming
a strategic imperative for online sellers. In a December 2007 report
entitled "Which Personalization Tools Work For eCommerce -- And Why,"
Forrester Research principle analyst Sucharita Mulpuru noted: "Web
site personalization is an underleveraged weapon... As the amount of
content online grows -- particularly on e-commerce sites that often
sell tens of thousands of different products -- and consumers are left
to wade through cumbersome experiences on their own, personalized
e-commerce experiences promise customer engagement and loyalty through
increased relevance. Enabled by external tools sometimes called
personalization engines, recommendation engines, discovery engines, or
behavioral targeting tools, personalization allows retailers to
increase relevance through activities like matching cross-sells to
customers based on interests or customizing clickstream paths based on
previous purchase or visit histories."

About CleverSet

CleverSet helps eCommerce companies and content providers
significantly increase their revenues by enabling a truly personalized
experience for each and every online visitor. The most powerful
solution in market today, CleverSet's recommendations service helps
companies entice people with relevant and personally appealing items
they might not have otherwise seen, improving each visitor's
experience and ultimately lifting conversion rates and
revenue-per-visitor. CleverSet's easy-to-deploy personalization
service can be operational within hours and begins improving business
results immediately. CleverSet is located in Seattle, Washington, and
Corvallis, Oregon. For more information about CleverSet and the
market-leading business results delivered by its e-commerce
personalization technology, please visit cleverset.com or call
1-206-965-8737.

About ATG

ATG (Art Technology Group, Inc., NASDAQ: ARTG) makes the software
and delivers the on demand solutions 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
provides customer interaction solutions to enhance conversions and
customer support, and delivers the world's most widely used
click-to-call service. ATG's solutions are used by over 900 major
brands, including Amazon, American Eagle Outfitters, AOL, AT&T, Best
Buy, B&Q, Cabela's, Carrefour, Coca Cola, Continental Airlines, CVS,
Dell, DirecTV, El Corte Ingles, Expedia, France Telecom, Harvard
Business School Publishing, Hewlett-Packard, Hilton, HSBC, Intuit,
Jenny Craig, Macy's, 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. The company is
headquartered in Cambridge, Massachusetts, with additional locations
throughout North America and Europe. For more information about ATG,
please visit www.atg.com.

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 http://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