AOL, Google, Microsoft, Yahoo Sued Over Competitive Bidding Patent from InformationWeek reports Performance Pricing filed a patent lawsuit (PDF document) against AOL, Google, Microsoft, and Yahoo over how they use competitive bidding within their search ad marketplace.

The patent, named Systems and methods for transacting business over a global communications, was granted in 2005, and covers actives such as "video games, electronic board games, crossword puzzles or other word games, sports betting, card games, or any other activity or combination of activities," InformationWeek reports. The patent holder feels it also covers the bidding methodologies deployed at Google AdWords, AOL Search Marketplace, Microsoft adCenter, and Yahoo Search Marketing.