Google's stellar first quarter results, which were buoyed by better than expected paid clicks data, has left the search giant sitting pretty, and comScore, the firm responsible for the numbers, holding the bag. But the truth is, most media buyers know better than to rely on either Nielsen or comScore alone.

"We have not expected the numbers to be 100 percent accurate," Sarah Fay, chief executive of both Carat and Isobar U.S., ad companies owned by Aegis Group, told The Wall Street Journal. "I think that comScore has been as good as anything we've had previously."  

While marketers may use comScore and Nielsen more for illumination than as hard-and-fast measures of the truth, the IAB has sought to resolve the frequent discrepancies that arise between the two firms.

At the IAB's request, both comScore and Nielsen have submitted to third-party audits so that marketers can better understand how each arrives at their respective numbers. That report is expected later this year.

As for the Google/comScore controversy, the matter seems to boil down to access. According TechCrunch, comScore is able to report on only a fraction of Google's total clicks. Google, not surprisingly, keeps data on searches performed outside of its network. For instance, Google tracks clicks made from Google-powered searches on portals like AOL. In theory, the inclusion of clicks from third-party sites should give Google, but not comScore, a better view of the total paid clicks picture.