At issue is what the IAB says is "a multiplicity of reported discrepancies in audience measurements" by the two companies.
IAB said both audience measurement companies have resisted numerous requests by the IAB and the Media Ratings Council since 1999 for independent audits. The Media Ratings Council was established by Congress in the 1960s.
"To persist in using panels that potentially 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," wrote Randall Rothenberg, IAB's president-CEO, in an open letter to Magid M. Abraham, president-CEO of comScore, and William Pulver, president-CEO of Nielsen//NetRatings. "And it certainly appears to us as if
these audiences are being undercounted or disregarded."