Both search engines, Google and Yahoo!, differentiate their paid listings from their free, contextual (otherwise known as "organic" results), usually by featuring the "sponsored links" searches on a different part of the page and by highlighting them in colored boxes. This is one of the quickest ways to pull lots of prospective customers to your web site and to get listed prominently in major search engines. If a visitor clicks on the advertisement served by Google AdSense or Yahoo! Search Marketing Solutions, the publisher/webmaster serving the ad earns a portion of the revenue that the advertiser is paying Google for the click.

However, both these PPC search engines also experience intermittent, yet explained, "spikes" that demolish your daily or monthly budget in a matter of minutes or hours. It's a little unnerving knowing that you could dissipate a couple thousand dollars in a matter of minutes with absolutely no recourse. Adequately staffed to handle these anomalies, both engines feature customer service representatives who often reply to such technical idiosyncrasies with hostile ambivalence. Both of these search engines employ software that will detect if the person who is advertising, for example, with adsense, they can determine if you are the one committing click fraud, whether by accident or on purpose and will stop those clicks from counting for you.

Sounds like an oxymoron, but it's not - Pay per click fraud is widespread, and prevalent. One of the main reasons that pay per click fraud is so rampant is that there are actually legitimate pieces of software that can used to commit pay per click fraud, although that was not the original intent for their creation. For instance, a click fraud artist may claim that he is just stress testing his analytics software program to ensure that it will catch click fraud. I won't mention which software programs commit click fraud, although a little investigation may turn them up.

Part of the problem with click fraud is that there are not yet any laws on the books dealing with the problem. The Federal Trade Commission (FTC) claims that they cannot really do anything about the problem because they are tasked with investigating consumer fraud, and cannot fit pay per click fraud into this category. However, the Department of Justice in the United States does have a rapidly growing division that deals with cases of Internet crime, and pay per click fraud will eventually come under their purview. The difficulty is that, even if you suspect you are a victim of click fraud, the onus generally falls on you to prove that it exists and to find those responsible. This is not an easy task.