Pay per click is a concept used in Internet advertising. This concept is used in search engines, advertising networks, and content websites like blogs. In this model of Internet marketing, advertisers pay only when any user actually clicks on an advertisement and visits the advertiser's website.

When this model is used in search engines, advertisers usually bid for a keyword phrase that is relevant for their target market. When a user types any keyword query matching an advertiser's keyword list in a search engine, or views any web page that contains material that is relevant to the advertiser, the advertiser's advertisement might be displayed. These advertisements are called 'sponsored links' or 'sponsored ads' and they appear by the side of or above the results on a search engine results page. These advertisements could be displayed anywhere else depending upon the choice of the webmaster or the blogger regarding its placement on the page. Content websites generally charge a fixed price per click instead of deciding it using any bidding method.

There are a number of PPC providers on the Internet of which Google AdWords, Yahoo! Search Engine and Microsoft adCentre are the largest of them and most well known. Minimum amount of money that is to be paid for each click would depend on the level of competition for that particular phrase or key word as well as the search engine used. This is often referred to as Cost per Click or CPC and it could be as low as US$0.01. But, it might be higher on more popular search engines. But, this model of Internet advertising is subject an abuse that is better known as click fraud.

Click fraud is a kind of crime committed on the Internet when a person, an automated computer script or a computer program that poses themselves as a legitimate user and goes on clicking on the advertisement link without generating any business, thus entailing huge cost to the advertisement without earning any benefit. But, the better-known search engines like Google and others have implemented automated systems to guard against such abusive use made by competitors or corrupt webmaster.

Pay per Click advertising when used in Internet marketing is definitely profitable and would bring you a lot of business but you should guard against such abuses like click fraud to avoid losing money.