Search engines sell "Sponsored Matches" space through third parties known as PPC (or CPC: cost per click, or PFP: pay for performance) search engines. These engines show their results on networks of search engines, ISPs and content sites.

The major pay-per-click search engine in North America is Yahoo! Search Marketing, which delivers paid results to many of the major search engine sites, including its parent company Yahoo! as well as MSN, Alta Vista, Sympatico.ca, CNN, InfoSpace and ESPN.

Yahoo! Search Marketing's main competitor in the North America is Google AdWords. Google is probably the most important search engine these days, and the innovative nature of AdWords has made that service an essential part of any extensive search engine marketing campaign. With AdWords, your ads' position is determined by bid price, click through rate (CTR), daily budget, campaign settings, match type—too many variables to be considered pure bidding. AdWords can therefore seem quite complex. Like Yahoo! Search Marketing, Google has numerous strategic partnerships with other properties, so your results also appear on many search engine sites and throughout their publications network. (Google offers you the option to choose which other properties on which you wish to appear.)

If you want to bid for some of the more popular search queries, both Yahoo! Search Marketing and AdWords can be very expensive. The smaller PPC engines may also be of use. Admittedly, almost none of them reach any of the major portals, but they do deliver results to a wide array of meta search engines, and so reasonably priced clicks are available.