A "cacaphony of complaints" from web publishers has prompted the Interactive Advertising Bureau (IAB) to put pressure on the industry's two major metrics firms to improve their methodologies and transparency, reports AdWeek .
The magazine says several top publishers have expressed doubts over the unique user and traffic data being provided by Nielsen//NetRatings and comScore Media Metrix, both of which are preparing to be audited.
IAB insiders apparently say independent researchers may be hired by the end of the year to examine Nielsen's and comScore's figures, although this has been officially denied.
According to AdWeek, the publishers say that the last six months to a year have seen the gap widening between their own analytics reports and the two companies' data.
Although sites losing traffic to rivals are bound to complain, and the measurement firms say discrepancies are down to differences between their methods and those of analytics providers, it seems likely the move will increase calls for them to combine sites' data with their own panel-based figures.
But as Jim Sterne wrote recently, this issue is also likely to get a lot more complicated with the adoption of Web 2.0 features.