If you're using AdWords or AdSense you must have heard about an emerging practice in the underworld of computing called "click fraud". But what exactly is click fraud and how is it accomplished?
Well AdSense uses a payment mechanism that awards a certain amount of money to a publisher (someone who holds an AdSense banner on their page) every time a person clicks on the said banner. So click fraud is the attempt to have people clicking the ads just so that they can earn a greater income.
There are people setting up sites for the sole purpose of fraudulently generating revenue through Google's AdSense program. These users achieve an incredible number of clicks through many methods, some complex and sophisticated and some rudimentary and simple.
One of the most complex is through the use of so called "hitbots". These are automated programs who emulate clicking the links in AdSense banners (there are some that actually click the banners as well).
Google's AdSense protection scheme is by no means perfect and nearly anyone can find the details of surmounting the protection mechanism, ironically just by doing a Google search.
Another, more rudimentary method is to hire a lot of people in a poor country to click the links on your site. This means these people will actually sit all day and just click links so you can earn a fortune. They come from very poor countries like India, and they're prepared to do so for just $0.50 an hour.
Of course, there's a problem with this mechanism. Once Google receives a large number of clicks from a single address, the address and the site that had the AdSense banner will be banned, and the illicit behavior might even get the fraudster sued.