In a development that would have seemed impossible two years ago, Google is cooperating publicly with Click Forensics, a click-fraud detection company with which it has had a rocky relationship.

Click Forensics said Thursday that Google has agreed to accept the electronically generated click-quality reports generated by the Click Forensics FACTr service. That means the process of documenting click-fraud instances and submitting reports to Google will be significantly automated and simplified for advertisers that use the FACTr service.

Google and Click Forensics make for strange bedfellows. The companies have sparred over the issue of click fraud, and the rhetoric has often approached ugly territory.

Google has accused Click Forensics of being inept in its methodology and misleading in its results in order to make the problem seem bigger than it is. Meanwhile, Click Forensics has charged that Google has purposefully trivialized click fraud and mischaracterized it as a minor problem.

Starring in the skirmishes have been Click Forensics President and Founder Tom Cuthbert and Google's expert on click fraud, Shuman Ghosemajumder.

Click fraud happens when someone clicks on an ad with malicious intent. For example, a competitor may click on a rival's pay-per-click ads in order to drive up their ad spending. Or a publisher may click on pay-per-click ads on its site to trigger more commissions.

Google generates almost all of its revenue from the type of online advertising that is most vulnerable to click fraud -- pay-per-click ads that appear along with relevant search results or in Web pages of relevant content.

Google declined to comment for this article, but Click Forensics CEO Paul Pellman said his company welcomes Google's cooperation in the FACTr (Fully Automated Click Tracking Reconciliation) service.

"From our standpoint, this is the first opportunity in which we've been able to implement something specific with Google, which is great," Pellman said.

Joseph Cowan, senior search strategist at Outrider, a search-engine marketing agency, said it would have been unheard of not long ago for Google to let itself be identified as a Click Forensics collaborator.

"Two years ago, it was a very adversarial relationship," said Cowan, whose company helps advertisers manage campaigns on Google and other search ad networks.

Outrider, which has been in business for 13 years, started offering Click Forensics click-quality services to its clients about two years ago. It realized at the time that click fraud went beyond scammers clicking on pay-per-click ads for malicious purposes, such as inflating their commissions or hurting competitors, he said.