The Washington Post reports that Advertisers Are Coming Up Empty with Google. Radiator.com, which spends $40,000 per month on Google found that 35% of paid clicks reported by Google were fraudulent, and that 17% of paid clicks on Yahoo were fraudulent. The Washington Post implies that nearly 1 in 3 to 1 in 5 clicks on Google are fradulent.

Radiator.com got a jolt this month from the firm it hired to audit the nearly $40,000 worth of sponsored links it buys every month from Google and Yahoo.

It appears that many of the clicks on the Web site's search-engine ads were made not by potential customers but instead by automated programs or people trying to drive up Radiator's advertising bill. Like other advertisers that place links on search engines, Radiator.com pays only when people click on the links.

After analyzing where and when each click came from, auditing firm ClickFacts Inc. estimated that 35 percent of the referrals that Radiator paid Google for stemmed from bogus traffic. Likewise, 17 percent of the leads that came from Yahoo search results were illegitimate.