Also called Cost per Click (CPC). A performance-based Online advertising pricing model in which Advertisers pay agencies and/or media companies on a cost per click (CPC) basis, according to the number of visitors that click on an Online ad or e-mail message. PPC advertising is different than “traditional” Online advertising, where Advertisers pay according to how many times their ad is displayed (see CPM). With Pay Per Click Advertising, an ad can be displayed many times, but the Advertiser only pays when a Web user actually clicks on the ad. (See Cost per click – CPC).