It originally planned to scrap the ‘live only’ data stream in January but delayed the change by three months to create “the smoothest possible transition” to the new metric, while acknowledging the controversy surrounding the decision.

Objections to the plan centred less on the introduction of ‘live plus same day’ ratings and more on the decision to eliminate “a stream of ratings desired by the buying community”, said Marc Goldman, chairman of American Association of Advertising Agencies’ media policy committee, who accused the research firm of “inserting itself into the buy/sell process”.

Nielsen, however, has always insisted that it made its decision based on five months’ worth of consultations with its clients and an “extensive review of data that showed that the three data streams to be supplied [‘live plus same day’, ‘plus three’ and ‘plus seven’ days] provide the best gauge of viewing”.

“We believe that a large majority of the industry favours this approach,” said Sabrina Crow, managing director of local television client services.

Nielsen said ‘live only’ data will still be available to clients via comparative data that is distributed weekly and monthly, as well as in custom reports and analyses.