Internet marketing / search engine optimization (SEO) metric. Also known as pay-per-click or pay-for-performance. These are processes managed by search engines and ad networks that are engaged by advertisers. The advertiser agrees a fee for each click on their ads and then the cost-per-click (CPC) is the amount of money that the hosting site earns each time a user clicks on the hosted advertisement. The CPC amount for any ad is determined by the advertiser through a bidding process. This amount will vary depending on the competitveness of the product and the amount that the advertiser is prepared to pay.