An online advertising campaign that a company pays for only when users interact with the ads. Instead of paying for your ads to simply show up on a publisher’s website, you pay for user clicks. Pay-per-click (PPC) refers to a type of campaign. Cost per click (CPC) refers to the actual cost: the campaign fee / number of clicks = cost per click. For example, if you pay $1,000 for a campaign that receives 50,000 clicks, your CPC is $0.02.