Study: Click fraud could threaten pay-per-click model | CNET News.com

Study: Click fraud could threaten pay-per-click model CNET News.com: "Online advertisers estimate that about 14.6 percent of the clicks on ads for which they're billed are fraudulent, costing them about $800 million last year, according to a study released Wednesday.
The study, called 'Click Fraud Reaches $1.3 billion, Dictates End of 'Don't Ask, Don't Tell' Era' and released by research and advisory firm Outsell, claims that 'Google, Yahoo and MSN...are stonewalling on click fraud, to their own and others' detriment.'
Search engines have refused to release figures on the amount of fraud in search advertising, most of which comes from Web sites boosting their revenue by clicking on ads on their own sites.
A recent study from the Click Fraud Network put the click fraud rate at 14 percent, while other companies that sell click fraud detection and prevention services have pegged it at 20 percent to 30 percent. Search companies say it is much lower than that and is under control.
The total effect of the $1.3 billion mentioned in the Outsell study represents $800 million spent on fraudulent clicks by advertisers and $500 million that advertisers say they no longer spend on pay-per-click advertising, the study said. Pay-per-click is the primary revenue "

More here