Jimmy Fallon: Nice kid, works hard, good pedigree, but ...

I sat through the conference call yesterday with Jimmy Fallon, the soon-to-be host of "Late Night with Jimmy Fallon" airing weeknights on NBC starting a week from Monday. As he did last month with TV critics at TCA, and as he has been doing every day on the video blogs at his LateNightWithJimmyFallon.com website, the former "SNL" fake-news reader has marketed himself as a network star perfectly suited to the G4 generation: interested in all of pop culture, bit of a geek, bit of a smartass ... in short, a candidate NBC decided could lead its second third-oldest late night franchise into the next decade and beyond.

So why am I starting to have my doubts?

I waited for my turn to ask a question on the call, which started 10 minutes late and ended three minutes early, but it never came. So instead of asking Jimmy Fallon this question, I'll ask it of you: Where exactly do you hope to draw your audience from?

This troubling question has gotten louder and louder in my head, as I've looked over the late-night ratings data and thought through the implications of Jay Leno's decision to stay at NBC. First, let's do the numbers:

• Since 2006, the 18-to-49-year-old audience for "Late Night with Conan O'Brien" -- the audience NBC and its advertisers are most interested in -- has declined 20 percent, from a 1.0 rating to a 0.8 rating. (I'm comparing season-to-date averages, not just grabbing at a single week's ratings.) During that time, Conan's audience has shrunk from 2.4 million to 2.0 million, and is in a virtual tie with Craig Ferguson for total viewership. However, he still retains a lead in the 18-49 demo of 0.2 (down from +0.3 in 2006).

• In that same time, Jay Leno's audience for "The Tonight Show" has declined from 5.9 million to 5.1 million per night. David Letterman's audience has also declined, but not nearly as much -- from 4.4 million to 3.9 million -- and in the demographic race, the margin has been cut in half, from a six-tenths-point advantage for Leno in 2006 to three-tenths today.

• Meanwhile, cable's share of the 18-49 audience is growing. Against Leno and Letterman, Comedy Central and Adult Swim each have built from an 0.6 rating to an 0.8 in the demo. O'Brien and Ferguson, Adult Swim is up a tick, from 0.3 to 0.4 in adults 18-49.

In the past I have written that Conan had little to worry about from competing with Letterman. But that was before Leno announced he was staying with NBC, and would be creating a fourth hour of late night at 9 p.m. CT. Initially I thought the idea was a good way for a failing, fourth-place network to salvage a situation that threatened to take away its dominance in late night. It certainly doesn't diminish O'Brien's luster to have Leno hanging around a few more years.

But as I've thought about it, I'm not convinced that NBC won't lose late night to CBS anyway.

Consider. Leno will be cannibalizing Conan's audience at 10:35. Based on notices I've gotten for months from readers, at the very least Conan will lose a lot of Leno's older viewers. Now, that would be OK so long as he maintained a clear demographic advantage over Letterman. But Leno will be taking some of those viewers away from Conan, too. NBC expects Jay to deliver a 3.0 demo at 9 p.m.; on some nights of the week the network is averaging far less than that. So he will be drawing from his base -- and that will give his base less reason to stick around, after their late local news, for Conan.

Meanwhile, Conan will come into direct competition not only with Stephen Colbert (who graced the show again this week, in a nice show of sportsmanship), but Adult Swim, which along with Comedy Central just keeps pulling younger viewers away from network TV.

While I think "Tonight" will continue to win comfortably over "Late Show" on CBS in the competition for total viewers, Leno's retention means that there will be four franchises, not just three, competing for the most valued viewership in late night, the 18-to-49-year-olds. And when O'Brien walks on stage at Universal Studios for the first time, he will have what now looks like a razor-thin 0.3 demographic advantage over Letterman.

But let's say he holds that advantage. Doesn't O'Brien have to take away from Fallon what O'Brien was able to inherit from Letterman -- a core audience of younger viewers? (There was no CBS competition in 1993 against "Late Night.") And if he does, won't Fallon start out with record low audience numbers? How does he possibly hope to build that up given the unprecedented competition for young viewers at 11:35 p.m. CT.?

If you thought O'Brien's ratings in 1993 were bad, wait until you see Fallon's ratings in six months. Unless he sets the world on fire -- and he's given few indications that he will -- he's going to be well behind Ferguson in overall ratings and just might be losing the demographic battle to him, too.

(Although just as an aside, a little friendly advice for Fallon: DON'T tell the press that "I don't want to overhype the first show" and act like it doesn't matter. Every late night talk show launched since 1982 has been remembered for its premiere episode, from Larry "Bud" Melman introducing David Letterman to the "Edelweiss" solo of Conan's debut to the "Chevy Chase Show" splashing down in a sea of flop sweat, and so on. Jimmy, just accept that the first show is overhyped, make it the best you can, and then use it for goodwill in the months to come.)

Let me emphasize that I like Fallon and I believe his show will be creatively enjoyable to watch, eventually, and that it will make every effort to recruit a new and younger audience to the "Late Night" franchise. In the press call Fallon put a lot of emphasis on his Internet site; the fact that he has three full-time bloggers; the vlog he's been faithfully churning out every day for weeks now; and his great affection for The Roots, the first hip-hop act to serve as a network late-night show house band.

But in the overall discussion of NBC's late-night situation, Fallon is the most vulnerable because he's untested and is in the most competitively vulnerable spot of anyone. Few people pay attention to "Last Call with Carson Daly," which has lost a quarter of its audience since 2006 and nearly half of its 18-49 viewership (from 0.7 to 0.4). There's a reason Daly was never in the "Late Night" conversation. But to those who have been given much, much will be expected. And if you don't think the future of NBC late night doesn't rest on Jimmy Fallon's shoulders, you're kidding yourself. He needs to succeed -- and he may well -- but he is the one, not Conan, whose position was hurt the most when Leno decided to stay on.

So to review: Jay Leno, who's not expected to average better than a 3.0 in the demographic, will lose prime time to big-budget scripted programs on CBS and ABC. Conan O'Brien, who will not enjoy the incumbency that Leno did, could lose the demographic race to Letterman, leaving his network in the awkward position of having its sales staff promoting a win in total viewers -- despite the fact that NBC sales has relentlessly ignored total viewer figures for more than a decade.

And Fallon could finish behind Ferguson, Kimmel and Adult Swim.

Is it any wonder David Letterman is rumored to be negotiating a ten-year contract extension with CBS?

As worst-case scenarios go, you could not possibly imagine a worse one for a network that squandered its historic position in prime time to now give up first place in late night. And to be clear, it is only a worst-case scenario. But I remember how close Conan O'Brien came to extinction in 1993 and '94 -- I chronicled it during the early months of Late Show News, which marked the beginning of my journalism career 15 years ago this week -- and I am just wondering out loud if NBC can afford to be so patient with Jimmy Fallon.