Last month's announcement that NBC will put The Jay Leno Show on every weekday at 10pm beginning next fall prompted CBS head Les Moonves to publicly state that his business was doing just fine, thank you very much.
CBS CEO Leslie Moonves reacted to the move by predicting that CSI: Miami (and presumably some of its other 10 p.m. shows) would beat Leno, “by a lot.” But even if Moonves turns out to be right, NBC could still succeed financially with the program because the cost of producing Leno is estimated at about $2 million a week, compared to $15 million or more to fill those same hours with sitcoms and dramas, which cost $2 million or $3 million or more per episode.
I'll go on record predicting that unless The Jay Leno Show is a complete failure (which I will define as less than a 2.2 rating for adults 18-49. For reference, the average 18-49 rating for The Tonight Show this season is a 1.3) that you'll see ABC and CBS trying the same thing within a year.
NBC's best 10pm weekday show last fall, Law & Order:SVU, averaged about a 3.7 rating for adults 18-49. There are other factors favoring scripted programming, including syndication potential, DVD sales, and repeatability. But if you're spending $15 million a week (for 22 weeks) to get a ~3.5 demo rating compared to spending $2-3 million a week for a 2.5 demo rating that's going to be a tough business move to pass up.