Priceline.com, an airline ticket bidding service that went online in April, has patented its business model. Patent No. 5,794,207 protects bilateral buyer-driven commerce, where buyers suggest a price and sellers accept or reject their offer. Priceline calls this a reverse auction. It used to be difficult to patent a business model, but since 1996 the practice has been recognized by the US Patent and Trademark Office and by the courts. As the Economist points out, it is becoming increasingly difficult to distinguish between the technology of a web site and the way it does business. Priceline, however, wants to take the idea a step further and license its newly patented business model to high-traffic sites like Yahoo! Inc.