Exhibit 99 Joint Filer Information Name: QK Holdings, Inc. Address: 3411 Silverside Road Bancroft Building, Suite 205C Wilmington, DE 19810 Designated Filer: Interactive Technology Holdings, LLC Issuer & Ticker Symbol: GSI Commerce, Inc. (GSIC) Date of Event Requiring Statement: 07/25/2003 Name: QVC, Inc. Address: Studio Park, 1200 Wilson Drive West Chester, PA, 19380 Designated Filer: Interactive Technology Holdings, LLC Issuer & Ticker Symbol: GSI Commerce, Inc. (GSIC) Date of Event Requiring Statement: 07/25/2003 Name: Comcast QVC, Inc. Address: 1201 N. Market Street, Suite 1405 Wilmington, Delaware 19801 Designated Filer: Interactive Technology Holdings, LLC Issuer & Ticker Symbol: GSI Commerce, Inc. (GSIC) Date of Event Requiring Statement: 07/25/2003 Name: Comcast Programming Holdings, Inc. Address: 1201 N. Market Street, Suite 1405 Wilmington, Delaware 19801 Designated Filer: Interactive Technology Holdings, LLC Issuer & Ticker Symbol: GSI Commerce, Inc. (GSIC) Date of Event Requiring Statement: 07/25/2003 Name: Comcast Holdings Corporation Address: 1500 Market Street Philadelphia, PA 19102 Designated Filer: Interactive Technology Holdings, LLC Issuer & Ticker Symbol: GSI Commerce, Inc. (GSIC) Date of Event Requiring Statement: 07/25/2003 Name: Comcast Corporation Address: 1500 Market Street Philadelphia, PA 19102 Designated Filer: Interactive Technology Holdings, LLC Issuer & Ticker Symbol: GSI Commerce, Inc. (GSIC) Date of Event Requiring Statement: 07/25/2003