Several weeks after David Letterman was shaken by a sex-and-extortion scandal, CBS' Late Show With David Letterman has shown little sign of weakening audience support.

Far from hurting the host's popularity, the headlines seemingly have had little impact on his late-night show and possibly even helped the series grow its viewership compared with last year.

It doesn't appear to have hurt him and likely got him more sampling, said Bill Carroll, vp and director of programing at consulting firm Katz Television Group.

Letterman enjoyed an unusually strong premiere week, bolstered by appearances by Bill Clinton and Barack Obama, before he revealed during the October 1 episode that he had sexual relationships with female staffers and was a victim of an alleged blackmail plot to keep those affairs secret.

Since then, Late Show's weekly average rating among adults aged 18-49, a demographic coveted by advertisers, has been a consistent 1.0 or 1.1 until it went into repeats last week. It has dropped slightly among total viewers, from an average of 4.4 million for a couple of weeks after his premiere to 4.1 million for the week before the repeats.

Season to date, Late Show is down 8% in the demo (1.1 average) and up 13% total viewers (4.4 million).

If that seems like a pretty mixed return, it's sunny compared to The Tonight Show With Conan O'Brien. With O'Brien now at the helm instead of Jay Leno, the NBC show is down 15% in the demo (1.0) and down 47% in viewers (2.5 million). As a result, CBS has shifted from being the perpetual late-night underdog to firmly leading Tonight among total audience and maintaining a slight edge in the adult demo.

Tonight's performance compared with Late Show also is impacted by each network's 10 p.m. story. CBS has bolstered its hour with The Mentalist on Thursdays and The Good Wife on Tuesdays, which have helped offset erosion in the time period during its other nights. Meanwhile, NBC's switch to The Jay Leno Show has given affiliates' local-news telecasts a notably weaker lead-in.

The potential upside for NBC is that its veteran Tonight franchise has demonstrated more stability week after week than Late Show, suggesting that O'Brien's ratings could have settled into a groove and Letterman's might have some softening ahead.

Letterman was the top story on the news for days running for quite a while and is still more on the minds of the general public than he's practically ever been before, a network analyst said. In a fragmented universe where achieving a 1 rating is a victory, having literally tens of millions of people buzzing about you is generally going to be a really big advantage.

For the networks' late-night second acts, the story is similar: CBS' The Late Late Show With Craig Ferguson (2 million, 0.6) has made gains among viewers, tying NBC's Late Night With Jimmy Fallon (1.4 million, 0.6) in the adult demo.

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