• by Wendy Davis  @wendyndavis, August 9, 2006

For the last several years, Google has been on the defensive about click fraud, with auditing companies accusing the search giant of overcharging advertisers to the tune of millions of dollars for invalid clicks. Tuesday, Google fought back. At a major industry conference, the search giant came out with a new report that accuses monitoring companies of methodological errors that result in inflated estimates of click fraud.

"Third-party click fraud auditing firms significantly overestimate the number of clicks occurring on an advertiser's account--and even more significantly overestimate the amount of 'click fraud' detected," states the 17-page report, which Google unveiled at Search Engine Strategies in San Jose, Calif. just as a panel discussion about click fraud was getting under way. "The most fundamental flaw that we have seen in these reports is the existence of fictitious clicks: events which are reported as fraudulent but do not appear within Google's logs as AdWords clicks."

Google maintains that click-fraud auditors overestimate invalid clicks--or clicks made by users with no good faith interest in visiting the marketers' Web sites--for two reasons. First, these 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 about the report.

For the study, "How Fictitious Clicks Occur in Third-Party Click Fraud Audit Reports," Google examined reports prepared by three click-fraud monitoring companies--ClickFacts, Click Forensics and AdWatcher.

A Click Forensics report from May 2 identified 6 clicks from the same IP address in a nine-minute period, according to Google. But Google records showed that the advertiser was charged for just two of those clicks, which were approximately seven minutes apart. (Google said in its report that advertisers sometimes are charged for clicks from the same IP address within a short time frame because "a user doesn't complete their research in a single visit to the advertiser's site.")

Google also referred to a May 3 report, in which Click Forensics appeared to have identified three clicks from the same IP address, but Google charged the marketer for just one click.

Click Forensics President and CEO Tom Cuthbert--a speaker at the click fraud panel during which Google issued the report--said the company had no advance notice of the allegations and needed time to investigate. "It took us all by surprise," he said, adding that the incidents mentioned by Google appeared to be "very isolated."

Google also took issue with reports by ClickFacts, stating that one report for Feb. 4 showed 54 clicks within 26 seconds--all from the same IP address to the same marketer. But Google said it only billed the advertiser for one 57-cent click from that IP address for the entire month of February.

ClickFacts Chief Strategy Officer Mikhail Ledvich said the company changed its methodology in May, after it learned of Google's criticism of the data.

But the Google study said the problems appeared to continue into June, when a report from ClickFacts showed one advertiser receiving three clicks from the same IP address, when Google had only billed the advertiser for a single click from that IP address. Ledvich, however, said that ClickFacts' June report was just a summary and didn't distinguish between paid and organic clicks.

Google also targeted AdWatcher in its report, stating that one AdWatcher report stated that Google overcharged an advertiser for about 12,000 invalid clicks in June, when in fact, Google charged the marketer for 6,000 clicks that month.

AdWatcher didn't return messages seeking comment for this article.