The suit, filed in the United States District Court in Chicago, also named six of Amazon's affiliated retail partners, including Borders Group, Target, Toys "R" Us and CDNow.
The lawsuit claims that Amazon violated Pinpoint's personalization technology patents--a service popularized by Amazon that allows e-commerce retailers to recommend related products or newer items to shoppers based on their purchase history at the site.
Amazon spokesman Bill Curry said the company had yet to review the suit.
Seattle-based Amazon finds itself on the other end of a lawsuit involving controversial patents known as business-method patents. In 1999,Amazon's patented 1-Click technology. Business-method patents go beyond protecting invented technology and actually involve patenting a business process.
Amazon's suit unleashed several more of its kind, includingand its Expedia service for infringing on Priceline's business model built around its technologies that allow consumers to "name their price" for products and services. Even .
Business-patent suits, however, have also come under criticism. Last fall, the head of the U.S. Patent and Trademark Office admitted that manyin the past.