Pay Per Click(PPC)
Pay Per Click (PPC) search engines are those that offer the marketing option called PPC. PPC advertising is the placement of a small ad on the search results page for a specific keyword or keywords in return for a specified payment when a visitor actually clicks on the ad. Advertisers pay nothing to appear on the results page per see; they only pay the amount they have agreed to (or bid for) when someone actually clicks on their ad and is taken to the landing page on their website. The term PPC means just what it says: the advertiser pays each time a visitor clicks on the ads. 
