Google AdWords is an online advertising service that enables advertisers to compete to display brief advertising copy to web users, based in part on keywords, predefined by the advertisers, that might link the copy to the content of web pages shown to users. Web pages from Google and from partner websites are designed to allow Google to select and display this advertising copy. Advertisers pay when users divert their browsing to seek more information about the copy displayed, and partner websites receive a portion of the income they generate.