Not all networks are ready to throw out the playbook. CBS is on track to raise its ratings this season, boosted by established juggernauts such as the "CSI" franchise and its new shows such as "The Mentalist."
David Poltrack, chief research officer for CBS Corp., contends that the network TV business isn't broken; it's just suffering from a temporary pullback in advertising.
"The recession is going to reduce the ad dollars that are available, but I've been through four recessions and that is expected," he said. "The advertising comes back with the recovery, and television comes out even stronger."
In the 1950s, late-night host Steve Allen successfully transitioned to prime time, but he eventually returned to late night with a syndicated show. He was an unusual case. Jack Paar and Dick Cavett tried and failed.