Click Fraud May Be Driving Up Your PPC Costs.

The persistence of click fraud has exposed a fundamental weakness in the promising business of Internet search marketing, but most advertisers aren't sure how to address the problem. In one recent example of the problem, law enforcement officials say a California man created a software program that he claimed could let spammers bilk Google out of millions of dollars in fraudulent clicks. Authorities said he was arrested while trying to blackmail Google for $150,000 to hand over the program. some marketing executives estimate that up to 20 percent of fees in certain advertising categories continue to be based on nonexistent consumers in today's search industry. Read more about it here