PPC, ideally, is supposed to split the revenues (from the clicks) between the publisher (search engine) and advertiser. More simply, every time someone (or something) clicks on a paid advertisement, both the advertiser and publisher are to receive revenue. This revenue sharing is how and why click fraud started.

Who are these people?
There are three main groups that click on pay per click ads without real interest in the offered goods: 

• People who joined Google AdSense or other per click affiliate programs click on the ads on their own web site to make a little income. Often, these people cooperate with other webmasters to click on each other's ads.
   
• Some unethical companies click on the pay per click ads of competitors to drive up their advertising costs.
   
• Companies (often in India, Russia and China) hire people who are paid to click on ads.

Is this really a big problem?
No pay per click company denies that pay per click fraud exists. According to some web analytics companies, as much as 50% of all click activity is fraudulent.

This means that your pay per click marketing activities are half effective as they could be because of click fraud.

What can you do to save money?
The best way to lower your pay per click advertising costs is to optimize your current ads so that they deliver a better return-on-investment.