Pay per click (PPC) is an Internet advertising process used on websites, advertisers pay only when their ad is clicked. With search engines, advertisers typically bid on keyword phrases relevant to their target market. Content sites commonly charge a fixed price per click rather than use a bidding system.
Cost per click (CPC) is the amount an advertiser pays search engines for a single click that brings one visitor to a website.
In contrast to the generalized portal, which seeks to drive a high volume of traffic to one site, PPC implements so called affiliate model, that provides purchase opportunities wherever people may be surfing. It does this by offering financial incentives (in the form of a percentage of revenue) to affiliated partner sites. The affiliates provide purchase-point click-through to the merchant. It is a pay-for-performance model -- if an affiliate does not generate sales, it represents no cost to the merchant. The affiliate model is inherently well-suited to the web, which explains its popularity. Variations include, banner exchange, pay-per-click, and revenue sharing programs.
Websites that utilize PPC will display an advertisement when a keyword query matches an advertiser's keyword list, or when a content site displays relevant content.
