Pay-per-click (PPC), also known as cost per click (CPC), is an internet advertising model used to drive traffic to websites, in which an advertiser pays a publisher (typically a search engine, website owner, or a network of websites) when the ad is clicked.

Pay-per-click, along with cost per impression and cost per order, are used to assess the cost effectiveness and profitability of internet marketing. Pay-per-click (PPC) has an advantage over cost per impression in that it conveys information about how effective the advertising was.