The concept of Pay-Per-Click or PPC advertising defines a marketing promotion model that is in wide use with search engines and advertising networks. Advertisers pay the site that displays their ads only when one of these gets clicked on, which in fact explains the name of the concept as such. All business owners activating online have certain keywords or key-phrases that define and address a target market. When someone researches for one of these keywords, websites will display not only page content but relevant ads too. Another name for such forms of advertising is sponsored links or sponsored ads, and they are nearly everywhere on search engine result pages.

The largest network operators providing the PPC advertising background are Yahoo!Search Marketing, Google Adwords and Microsoft adCenter. The prices practiced by these service providers are similar in terms of packages, but high variations appear within each pattern under the pressure of a higher or lower level of demand for a certain key phrase. There are several ways of conducting PPC advertising campaigns and lots of businesses actually higher professional agencies to do this part of the Internet marketing promotion from A to Z. Thus, there are two types of campaigns with their specific categories: content match and sponsored match.

Thus PPC advertising focused on content match develops campaigns that use the business web site or other pages together with newsletters and e-mails to target more relevant visitors and thus generate profit. The sponsored match variant on the other hand involves only the ad display on the result pages in search engines. Thus, the advertiser makes profit when the click on the ads results in a transaction, while the displayer, whether website or search engine makes profit with every click on the ads regardless of whether they are profitable for the advertiser or not.

The problem with PPC advertising is that it represents a model that has often been subject to click fraud. This means that dishonest people often click on ads just to ruin the competition by increasing the pay-per-click total costs and thus make business unprofitable. The other situation is when the websiter displaying an ad orders the clicks on the ads to generate more money. Google and the other search engines have taken all sorts of measures against such abuses, and the main safety program consisted in the implementation of automated systems capable to detect fraudulent clicking. Yet, the system is not 100% safe and breaches do exist.