• by Wendy Davis  @wendyndavis, January 31, 2007

Click fraud rates reached 14.2% last quarter--up from 13.8% in the third, according to a new report by click fraud auditing company Click Forensics.

The click fraud rate for keywords that cost more than $2 was even higher--20.9%, according to the report. The study was based on data gathered from Click Forensics' "Click Fraud Network" of more than 2,500 online advertisers and agencies.

But Click Forensics' numbers are by no means universally accepted. Search company Google, for one, has gone on record as disputing the Click Forensics reports. Last year, the search giant issued its own report on click fraud, "How Fictitious Clicks Occur in Third-Party Click Fraud Audit Reports," which criticized the methodology of Click Forensics as well as two other companies, ClickFacts and AdWatcher.

Google maintains that click-fraud auditors overestimate invalid clicks--those made by users with no real interest in visiting marketers' Web sites--for two reasons. First, auditing companies reportedly count page reloads as separate clicks; secondly, they wrongly count one advertiser's traffic in another's report. "A rigorous technical analysis by Google engineers has found fundamental flaws in the work of several click fraud consultants--flaws that help explain why widely quoted estimates of the size of the click fraud problem are exaggerated," wrote Google's Shuman Ghosemajumder, business product manager for trust and safety, in a blog post last year about the report.