Pay-per-click (PPC), also known as cost per click (CPC), is an internet ad model used to direct traffic to websites, in which an advertiser pays a publisher (typically a website owner or a network of websites) when the ad is clicked.
Pay-per-click is commonly associated with search engines (such as Google AdWords and Microsoft Bing Ads). With search engines, advertisers typically bid on keyword phrases relevant to their target market. In contrast, content sites commonly charge a fixed price per click rather than use a bidding system. PPC “display” advertisements, also known as “banner” ads, are shown on web sites with related content that have agreed to show ads and are typically not pay-per-click advertising. Social networks such as Facebook and Twitter have also adopted pay-per-click as one of their advertising models.