American Cancer Society Chooses Siebel eBusiness Applications; Nation's Top Volunteer Health Organization Streamlines Event Marketing and Constituent Services.

Business Editors/Health Writers

SAN MATEO, Calif.--(BUSINESS WIRE)--Sept. 30, 2002

Siebel Systems, Inc. (Nasdaq:SEBL), a leading provider of multichannel eBusiness applications software, today announced that the American Cancer Society has selected Siebel eBusiness Applications to coordinate its events-based marketing and constituent service processes. The proven best practices contained in Siebel Call Center and Siebel eEvents will allow the Society to have at its fingertips data needed to enhance the support and education it provides to millions of Americans, while streamlining its fund-raising activities.

"Our ultimate goal is to make more resources available in the fight against cancer," said Terry Music, National Strategic Business Manager, Cancer Information for the American Cancer Society. "We need to deliver programs and services at the same level as a for-profit organization. This software should allow us to engage in more personalized interactions with our constituents and provide optimum service through multiple touchpoints. We're confident that it will lead to even better relationships with our dedicated supporters and better service to people affected by cancer."

Siebel Call Center replaces an assortment of existing technologies to create a single, comprehensive view of constituent interactions with the organization, which occur through multiple channels including phone, email, and Web. The new platform centralizes operations for the organization's 17 divisions, helping make the Society more efficient and an effective caretaker of donor support.

After a cross-organizational evaluation process, the Society initially deployed Siebel Call Center in its Planned Giving Group. The software has consolidated information from several databases within the organization, giving staff access to detailed records to help identify opportunities for further developing constituent relationships with the Society. Siebel Call Center will soon be deployed to staff nationwide.

The American Cancer Society recently selected Siebel eEvents to coordinate and streamline its fund-raising events, from planning and registration to execution and analysis. Events are a key revenue generator for American Cancer Society, responsible for a significant portion of its donations. For example, the Society's national signature event, "Relay for Life," the world's largest fund-raising activity, includes more than 2.5 million participants, including 500,000 cancer survivors, who participate in 3,300 events nationwide. Relays are resource-intensive events, involving complex coordination among the Society's vendors, partners, volunteers, and staff, each of which has its own logistical, operational, and follow-up requirements. American Cancer Society employees who work on events planning now rely on Siebel eEvents as their complete solution for planning and executing a wide range of activities to reinforce donor and volunteer relationships.

About the American Cancer Society

The American Cancer Society is the nationwide community-based voluntary health organization dedicated to eliminating cancer as a major health problem by preventing cancer, saving lives, and diminishing suffering from cancer through research, education, advocacy, and service.

For more information about cancer, call toll-free anytime 1-800-ACS-2345 or visit the American Cancer Society Web site at www.cancer.org.

About Siebel Systems

Siebel Systems, Inc. is a leading provider of eBusiness applications software, enabling corporations to sell to, market to, and serve customers across multiple channels and lines of business. With more than 3,500 customers worldwide, Siebel Systems provides organizations with a proven set of industry-specific best practices, CRM applications, and business processes, empowering them to consistently deliver superior customer experiences and establish more profitable customer relationships. Siebel Systems' sales and service facilities are located in more than 28 countries.

Except for the historical information contained herein, this press release contains forward-looking statements that involve risk or uncertainties. Future operating results of Siebel Systems may differ from the results discussed or forecasted in the forward-looking statements due to factors that include, but are not limited to, risks associated with customer relations, such as the availability of Siebel Systems' products and services, customer implementation of products and services, relationships with customers, third-party vendors and systems integrators, concentration of revenues in a relatively small number of customers, existence of errors or defects in products, ability to successfully manage growth, significant current and expected additional competition and the need to continue to expand product distribution and services offerings. Further information on potential factors that could affect the financial results of Siebel Systems are included in Siebel Systems' Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and its other filings with the Securities and Exchange Commission, which are available at www.sec.gov. Siebel Systems assumes no obligation to update the information in this press release.

Note to Editors: Siebel is a trademark of Siebel Systems, Inc. and may be registered in certain jurisdictions. All other product and company names mentioned are the property of their respective owners and are mentioned for identification purposes only.