Cost Per Click, also known as PPC, CPC or Pay Per Click in internet marketing refers to an arrangement when an advertiser pays the publisher only when their ads are clicked. With search engines and marketing companies advertisers generally bid on specific keywords that are relevant to the nature of their products and services.Cost Per Click generally refers to the actual cost of advertising, whereas PPC (or Pay Per Click) refers to an advertising arrangement, such as PPC Program.Cost Per Click is the most widely used pay-for-performance advertising arrangement. Conversion rate in this program is one of the most important metrics to advertisers, whereas for publishers, Click through rate (or CTR) is the main indicator of monetization effectiveness.