The online ad industry group today asked two leading Internet metrics firms, comScore and Nielsen/NetRatings, "to submit to a third-party audit of their measurement processes."
The IAB's avowed goal is "to achieve transparency in audience counts and to revise out-of-date methodologies," such as the use of audience panels.
In an open letter to the two firms, IAB president and CEO Randall Rothenberg said audience panels, invented to measure radio audiences seven decades ago, represent an antiquated, inaccurate approach.
"To persist in using panels that undercount or ignore the diverse populations that are the future of consumer marketing is to deny marketers the insights they need to build their businesses," Rothenberg's letter states. "And it certainly appears to us as if they are being undercounted or disregarded, for our members' server logs continue to diverge starkly from your companies' sample-based assessments, by 2x to 3x magnitudes in some cases -- far beyond any legitimate margin of sampling error."
The 332 members of the IAB account for 86% of the industry's interactive advertising spending.
In response to the letter, comScore offered the following statement: "comScore welcomes the objective outlined in the IAB open letter of achieving transparency in our panel methods. To that end, we began working with the MRC [Media Rating Council] several months ago as part of an audit of our methodologies. We intend to continue that effort. And we're also in the final stages of an evaluation of our methodologies by the Advertising Research Foundation. We're confident that our methodologies will withstand the scrutiny of third-party evaluation."
Nielsen/NetRatings did not respond to a request for comment.
Rothenberg wants to do away with the "bad customs that have hindered older media and angered advertisers for decades," such as "inadequate samples," "phantom metrics" and "metering technologies and processes that are easy to game."
But the new technology may be as fallible as the old. On Monday, comScore said that cookie-based audience measurement overstates the size of Web site audiences. Cookies are small files accepted by most Web browsers that companies use to track visitors.
ComScore's study found that 3 in 10 U.S. Internet users frequently delete cookies from their computers. Thus, "Web site server logs that count unique cookies to measure unique visitors are likely to be exaggerating the size of the site's audience by a factor as high as 2.5, or an overstatement of 150%," comScore said.