Online advertising still is rapidly booming on record highs each day. The efficiency in terms of cost and audience coverage entices *various online businesses* to go on online advertising to generate high-rocketing sales. But just like any endeavor, there is also another side to the good story of the success of online advertising-- click fraud.

Click fraud happens in pay per click (PPC) online advertising when a web user, automated script, or computer program mimics a legitimate browser of a website with the intended purpose of generating a fraudulent charge per click. There exists two known ways of generating fraudulent clicks: manual clicking (by humans) and automated clicking (by software). Whatever the means is, fraudulent clicks are known to be acts of competitors and sometimes even affiliate programs and traffic partners.

The primary source of fraudulent, erroneous clicks is the PPC advertising. In PPC, the system of revenue sharing among the publisher, advertiser, affiliate program, and the advertising network (acting as middleman) is susceptible to rampant click fraud. The identified secondary source is the non-contracting parties. These non-contracting parties are not, in any way, part of any PPC agreements; fraudulent clicks from this source are way harder to monitor and avoid since culprits cannot be held legally liable for breach of contract. Non-contracting parties can be classified into four groups: competitors of advertisers, competitors of publishers, parties with malicious intent, and unwanted connections of the publisher. Competitors of advertisers harm advertisers in the same market by clicking on their advertisements. They do not profit directly, but their acts directly force advertisers to pay for clicks that are essentially irrelevant. This practice weakens and eliminates a source of competition. Competitors of publishers are parties that do their thing by framing a publisher and making it appear that the publisher is clicking on its ads. If the advertiser finds out and is deceived by the ploy, termination of the advertiser-publisher agreements usually follow. Since most publishers rely solely on revenues from advertisers, termination of their relationship then weakens the publishers and the competitors gain advantage. Parties with malicious intent, on the other hand, harm either or both the advertiser, (even the affiliates) and the publisher. The malicious, impertinent clicks they make are aimed at political and personal gains over the legitimate parties. Parties with malicious intent are very hard to track down. Unwanted connections of a publisher are those who are not formally involved in the contract between the publisher and the advertiser and who do fraudulent clicks to help boost the gains of the publisher. This, somehow, can be called an inside job.

But these four classifications are only small in scale and magnitude compared to syndicates who do organized fraudulent clicks. Cyber syndicates do their dubious acts by using numerous computer units that are equipped with their own internet connections in different geographic locations. Most commonly, syndicates and cyber crime networks make use of the *Trojan code* to turn the average person's computers into programmed-clicking machines that use sporadic redirections or poisoning of domain name system. This then transforms the unsuspecting user's actions into actions generating revenue for the syndicate.

Proving, litigating, or accounting of fraudulent, irrelevant clicks are something that are currently very difficult to do. Just like any other cyber crime, culprits behind click fraud benefit from the vast anonymity in the cyberspace. The closest publishers and advertisers can do is to employ stringent monitoring measure to at least mitigate the whooping costs of generating fraudulent clicks. Most companies resort to forensic analysis and third-party corroboration to hasten the damages of fraudulent, impertinent clicks. A forensic analysis is an in-depth look at the source and behavior of the clicks being made in a particular advertisement or sets of advertisements. The log files that are in custody of the advertisers are the main reference for making a forensic analysis. Third-party corroboration basically involves an independent body, which monitors or probes the clicks being made on advertisements. A popular third-party which offers web-based solutions on fraudulent clicks and other cyber crimes is the Clicks Forensics.

In July 2006, Click Forensics reported that of every ten clicks being made in one advertisement, one is surely fraudulent. Direct Marking Association, another agency concentrated on finding cure for click fraud, estimates that of the $1.3 billion average annual cost among advertisers, $500 million go to lost business-- mostly from click fraud. Click Forensics offers services such as commissioned reports and analytics for PPC engines and search engines. Search engine honchos Google and Yahoo!, however, have their own safety nets to protect their interests and that of their advertisers.