• by David Goetzl  @dgoetzl, January 19, 2009

Any fears that broadcasters had about the switch to C3 ratings slashing their inventory might seem unfounded now. So far this season, of the four major broadcast networks, two have gained monetizable inventory with the new metric, while two have seen it hold steady.

The industry used "live program ratings" as the negotiating currency for decades. In 2007, it switched to what's known as C3--derived from commercial ratings in the live broadcast and over the ensuing three days with DVRs.

This season, "live-only program" ratings for ABC and Fox are the same as each network's C3 numbers. In the 18-to-49 demo, ABC has a 2.7 "live" figure--the same as its C3 ratings average. Fox, similarly, has a 2.5 in both metrics.

CBS has seen a slight bump from a 2.7 "live" to a 2.8 in C3. NBC has risen from a 2.6 to a 2.7, when comparing "live" to C3.

The figures cover Sept. 22 through Dec. 21 and were compiled by Magna Global. A year ago at the same point in the 2007-08 season, the data showed that all four networks had the same "live" number as C3.

On one level, it would seem that enough people who view shows with DVRs are watching commercials to keep the "old" ratings about on par with the new ones.

That's not to say that networks don't have ratings issues or revenues are not affected--pricing is obviously driven by supply and demand. It's just that impressions on the market have not been driven downward by the switchover.

In fact, with C3 ratings, there is ample evidence that networks are experiencing ratings woes.

All but CBS have seen their C3 ratings decline notably this year, compared to their performance last season. CBS has been flat in 18-to-49 at 2.8. But Fox is down 14%, from a 2.9 to a 2.5. ABC has dropped 13% from a 3.1 to a 2.7. And NBC has fallen 7% from a 2.9 to a 2.7.

CBS--the network that had less appeal to younger viewers for many years--is now the 18-to-49 leader, at least in the C3 metric that drives sales. CBS is at a 2.8, with ABC and NBC at a 2.7 and Fox at a 2.5.

Note: the numbers do not include "American Idol."