Ratings erosion continues to plague broadcast networks

Broadcast ratings at the major networks have fallen 10 to 17 percent in the 18to 49 demographic at about three-quarters of the way through the 2010-2011 TV season. At the same time, cable networks have seen slight improvements in ratings. Since 2001, the Big Four networks are down collectively about 35 percent in the key 18 to 49 demographic.

This was the finding of a new report from Turner Research and Nielsen, which looked at the broadest measure of TV viewing, live program plus seven days of time-shifted viewing, from Sept. 20, 2010, through March 20, 2011.

Fox is the leader among the Big Four broadcast networks. It made a rapid improvement from a poor start last fall, when it was down double-digit percentages versus a year ago. Fox is averaging about 4.6 million adult 18 to 49 viewers, down 6 percent. The other networks were all down much more. CBS is at 3.9 million, off 10 percent; ABC is at 3.202, also down 10 percent; and NBC came in third at 3.198, off 17 percent.

A year ago, NBC aired the Vancouver Winter Olympics in February, which took viewers away from all other networks. But this year, NBC lost viewers, down 35 percent to 2.7 million. Even taking the Olympics out of the equation, NBC was down 11 percent.

Overall, the network picture was grim. Season-to-date, the Big Four networks are down 11 percent in 18 to 49 viewers (to 13.5 million) and off 16 percent in the first quarter 2011 (to 13.4 million). Ad-supported cable, on the other hand, was up 3 percent to a collective 18.5 rating among 18 to 49 viewers during the period.