At a time when so-called “viewable impressions” are emerging as the industry standard for most digital media buys, Nielsen is integrating three of the leading verification providers -- DoubleVerify, Integral Ad Science and Moat -- into its digital media ratings system.

The move is consistent with Nielsen’s history of integrating third-party data providers and processors of its ratings data to enable clients -- advertisers, agencies and publishers -- to analyze audience estimates based on the way they want to visualize them.

Nielsen did not say if and when other “viewability providers” would be integrated, but the companies it is starting with are more or less the Big 3 of digital viewability measurement. All have some form of accreditation from the industry ratings watchdog, the Media Rating Council.