Content Matching is the act of matching your ad to particular content sites based on relevant keywords.  Content matching is a pay-per-click option where PPC providers (ie. Google AdSense, Yahoo! Content Match™, etc) place ads on non-search-engine websites that contain content that ‘matches’ the ads. The ‘very sound’ idea behind this concept is that people who are interested enough in a given subject to be visiting a page devoted to the subject should be ideal target customers for the ads in question. For example, if your ad is for cookware, then a website devoted to cooking should be a good place for your ads to be shown.