(FSB Magazine) -- Google may have revolutionized business (see "Get Right With Google," page 70), but a recent class-action lawsuit against the company has focused attention on a side effect: click fraud, in which an advertiser's competitors repeatedly follow its pay-per-click ads in an effort to run up its advertising costs. (Google has said it will disclose its false-click rates to advertisers.) A recent study by San Antonio's ClickForensics, a click-fraud detection firm, found that businesses that pay the most for search terms may be the most vulnerable.

14% Overall rate of search-engine clicks that were fraudulent during the second quarter of 2006.

20% Average fraud rate for search terms that cost more than $2 a click.