In late February, a patent for an Internet-based customer referral system issued to Amazon.com. Not long afterward, a British company sent out a press release claiming to have put similar technology in place several years before Amazon even filed for a patent.

Amazon’s ’141 patent for the customer referral system issued on Feb. 22. The technology allows other Web sites to refer customers to Amazon in exchange for a fee paid by the bookseller. Amazon applied for its patent in 1997.