• by Wayne Friedman , David Goetzl  @dgoetzl, September 15, 2009

Content with the strong ratings for night one of "The Jay Leno Show," NBC Universal CEO Jeff Zucker took a cautious approach to its future Tuesday. The show's much-anticipated launch faced weak competition.

After all, TV history is littered with high-profile shows debuting impressively before fizzling. A notable example: Katie Couric's debut with robust ratings as anchor of the "CBS Evening News" in 2006 before the show sank to third place.

The new 10 p.m. "Leno" -- which critics say looks awfully similar to his late-night talk show -- pulled in a big Nielsen preliminary 5.1 rating/13 share among 18-49 viewers, and 17.7 million viewers overall.

That's not surprising, given its weaker rivals.

CBS aired a drama repeat against it, and ABC ran with a movie. ESPN was the strongest competitor, offering its "Monday Night Football" season debut. Still, "Leno" was the top-rated broadcast network program for the night. The summer's top-rated show -- NBC's "America's Got Talent" -- was its lead-in, scoring a 3.6 rating at 9 p.m., on par with recent performances.

"It's had a lot of things going for it," says Brad Adgate, senior vice president and corporate media director for Horizon Media, the media agency that has NBC as a client. He cites its hit lead-in, as well as the big marketing push behind "Leno."

In comparison, when "The Tonight Show with Jay Leno" went off the air in May, Leno's last episode earned a 3.4 rating among 18-49 viewers and 11.9 million viewers.

NBC executives and other media analysts say the network will consider the new show a success if it averages at least a 1.6 to 1.7 rating among 18-49 viewers, which is about "The Tonight Show" average. Nielsen Media Research says the actual broadcast season begins Sept. 21.

One promise of the "Leno" show: NBC is committing to fresh episodes for nearly 52 weeks a year -- rather than just a nine-month broadcast season. And Zucker, speaking at an investor event, said: "We're going to judge this on 52 weeks. The fact that it opened so well -- we feel great about that. But it's only one day."

Zucker reiterated several other advantages that "Leno" can provide: a counterbalance to fewer hit comedies in prime time, and "DVR-proof" programming -- both of which should attract advertisers.

"Advertisers want comedy," Zucker said. The show's attempt to be topical each night could cut down on the amount of time-shifted viewing and attendant commercial-skipping. "There's no reason to believe there's going to be any less [ad zapping] going forward," Zucker said. [Launching "Leno"] is an acknowledgment of that fact."

Also, NBC (and apparently Leno himself) are willing to offer product integration opportunities, Zucker said.

Still, Zucker acknowledged that ad prices are below competing 10 p.m. dramas on ABC and CBS. In fairness, "Leno" will cost less to produce, offering an upside in profitability. Although a 1.6 or 1.7 rating would be a failure for TV dramas in the period, NBC will make money with Leno in the time slot. The new Monday through Friday "Leno" is believed to cost $100 million a year versus the $300 million in annual production costs airing one-hour drama programs.

What is still to be determined is how local NBC affiliates fare with "Leno" as their lead-out to local newscasts. Analysts say NBC will be hard-pressed to make changes if the "Leno" schedule brings in fewer viewers for local news efforts.

No one will judge "Leno" solely on his debut numbers. Reminds Adgate: "It's a marathon, not a sprint."