In 2004, DoubleClick bought Performics for $58 million and came out with the DoubleClick's Performics affiliate ad network, a system which pays publishers after users click on an ad and make a purchase or take some other action. Now, after Google's acquired DoubleClick, its rebranded the network as the Google Affiliate Network, signaling the search giant's entry into cost-per-action advertising, after tentative experiments. [News.com]