Meanwhile viewers should start complaining, because now a bunch of commercials will interrupt the usual relatively commercial-free first half hour of your favorite late-night network talk show.

Jokes in those monologues that need a lot time to develop will now need to be rewritten. CBS has already been experimenting in running early-in-the-show commercials this summer during "The Late Late Show with Craig Ferguson" - all because of the coming commercial ratings, which are replacing program ratings as the main currency for TV advertising deals.

Good news: David Letterman typically has only has about three bits in his short monologue. That means early commercials - like those for young-skewing products, theatrical movies, videos, and mobile phone companies - can be easily squeezed into the early part of his show. The same can't be said for NBC's Jay Leno, who seems to have an extra-long initial monologue - seven or eight bits for his intro.

Because viewership is higher earlier in the evening, commercials - now subject to commercial ratings - will run earlier.