NEW YORK: US TV ratings provider Nielsen Media Research has delayed indefinitely the launch of its commercial ratings data service as arguments rage again between agencies and television broadcasters over live viewing versus ads watched later on DVRs.

Nielsen's system, scheduled to start mid-December, was set to measure how many people watched a commercial when it was broadcast live or on playback in the ensuing seven days. The new information was touted as the future currency for network TV airtime sales [WARC: 12-July-06].

However, the company released a new analysis last week that appeared to suggest around 90% of viewers have watched the ads within three days of recording a show, while only 1% are watching at the seven day point.

This revelation has reignited the debate between networks such as ABC and NBC - that want to be paid for viewers watching shows on DVRs - and the agencies which are only willing to pay for live viewing. The latter's wishes have so far prevailed.

In a letter to clients Nielsen says: "We concluded that the best course of action is to have, as soon as possible, further discussions with national clients regarding the possibility of a new data stream for commercial-minute data in order to ensure that the data file that is released contains the information that clients need."

All parties had hoped the system would be up and running in time for the 'upfront' airtime sales next May. This latest latest failure to launch makes that deadline more difficult to meet and could have a knock-on effect on TV companies' finances. See CBS story below.

Data sourced from; additional content by WARC staff