In a report sent to investors this morning, Wall Street analyst Brian Wieser says both companies’ claims of dominance are likely specious and irrelevant. Citing recent claims by comScore that 25 of the top 25 advertisers currently use its online audience ratings vs. Nielsen’s claim that 20 of the top 25 advertisers use its version, Wieser says something didn’t add up, so his team at Pivotal Research Group did some research of its own, reaching out to “several of our industry contacts to get to the bottom of the “dueling” claims by the online measurement services.
Source: comScore, Nielsen Battle Over Estimates: Not Users, But Advertisers 05/15/2015