Nielsen says it will start delivering its first ratings for national TV commercials to broadcast and cable network clients beginning Dec. 11. The service will be free to begin with and include historical data back to the beginning of the season.
Advertisers have been clamoring for commercial ratings for some time so that they can better gauge the bang for their buck.
Nielsen had initially set Nov. 18 as the date, but it needed the extra time for some modifications to the original specs, it said.
Nielsen will provide an average rating for all national commercial minutes in a program, rather than rating a specific spot. For example, if there were 12 national spots in CSI, it would add them up and divide by the number of spots, though each spot will be weighted according to rating for the portion of the program minute in which it appeared.
For example again, a spot that aired in the last 15 seconds of minute 12 and the first 15 seconds of minute 13 would be weighted according to the audience for each of those minutes.
The definition of a commercial minute will exclude PSA's and infomercial time, but will register as a "commercial minute" for averaging purposes if it contains as little as one second of commercial time.
After input from clients, Nielsen has decided to make it an opt-in system, which means that if TV and cable networks want to get the commercial ratings data, they will have to let Nielsen know by Nov. 1.
Nielsen has also made the first year's worth free--"everybody likes free beer," says Nielsen spokesman Jack Loftus. That will give them a chance to kick the tires, he suggests, after which the company will probably start charging in year two.
Nielsen updated clients on the progress in a letter Wednesday.