A search engine in which the ranking of your Web site is determined by the amount you are paying for each click from that search engine to your site. Think of Pay-Per-Click search engines as a low-cost advertising method. Examples of Pay-Per-Click search engines are Overture, FindWhat, Search123, etc.
a search engine where you place your advertisement listings and which charges you a pre-determined or pre-set amount every time someone clicks on your listing. The idea is, if no one visits your site, you don't have to pay.
A search engine that offers pay-per-click advertising as an option to businesses.