Pay Per Click Advertising is a common advertising method found mainly on search engines and content sites. This is called pay per click because the host site is only paid when the advertisement link on their website is clicked on. The most common type of pay per click advertising is done with a flat rate. This is when a predetermined amount of money is paid EVERY time the advertisement is clicked on.
Pay per click is efficient because it keeps track of the amount of people who clicked on the advertisement. It keeps things simple. It also encourages competition between advertisers. Many times, the ads use a keyword or two in order to catch more attention. Not everybody can use the same keywords. Often, these advertisers will bid for the keywords they want to use. Pay per click advertising is a good and accurate way to advertise on the internet.
However, everything has its flaws. With pay per click advertising there is click fraud. This is when the same person repeatedly clicks the same ad in order to get money for the host site. This can be preventable with some search engines like Google that keep track of ISP numbers in order to ensure that different people are clicking on the ad.