Next week will see the release by Nielsen Media Research of revised viewing data for the 2002/02 period – updated to take account of the 2000 US Census

Significant changes are expected to the viewer numbers previously reported for primetime TV shows, triggering frenzied renegotiation between networks and media-buyers to compensate for the predicted wave of viewer under- and over-deliveries.

The cashbacks will be two-way dependent on the age of viewers, as the 2000 census revealed that Americans between the ages of 2-11 had declined numerically since the last survey in 1990. On the obverse side of the coin, the population in most age groups between 12-34 has risen.

So the revised Nielsen data will show under-delivery among the majority of children’s programming, particularly by specialist cable operators such as Nickelodeon, Cartoon Network and much of WB’s business; whereas networks primarily targeting viewers in the 12-34 and 18-34 age groups (Fox, MTV, UPN and WB primetime, for example) will have over-delivered on their audience guarantees.

The holy grail both for advertisers and networks, the 18-49 demographic, has barely been affected by the census-adjusted data, with viewing numbers up only a fraction.

But the phonelines are expected to run hot when the new data is published. Says Fox Broadcasting sales president Jon Nesvig: “We're going to have to look at individual cases and talk with each advertiser and try to come up with a solution. We need to figure out a way to get some value [from advertisers] for the true audience we delivered for each show this past season.”

There is less euphoria on the other side of the fence: “I knew they [Nielsen] were planning to issue new estimates for the 2002-03 season based on the 2000 Census numbers, but not to revise this season’s estimates,” said one top buying executive.

Data sourced from: AdWeek.com; additional content by WARC staff