When Fallon premiered on "Tonight" during the Olympics, the franchise hit numbers unseen since Johnny Carson's last week in 1992. Things have settled down but Fallon is still comfortably on top. During the week of March 10-14, Fallon averaged 4.26 million viewers to Jimmy Kimmel's 2.83 million on ABC and David Letterman's 2.78 million on CBS, the Nielsen company said. Fallon has consistently topped the 4.1 million viewers that Leno averaged this season before leaving.
Fallon's lead over his rivals is more pronounced among viewers aged 18-to-49, the demographic NBC bases its advertising sales upon.
Fallon and NBC embrace the way many early-to-bed consumers experience late-night television these days: by watching clips of a show's best moments online. The YouTube clip of Fallon and Will Smith acting out the evolution of hip-hop dancing has been seen more than 12.8 million times. Fallon's lip-sync duel with Paul Rudd on songs by Tina Turner, Foreigner and Queen has nearly 9 million views.
Other popular clips show Fallon, singer Idina Menzel and the Roots performing "Let it Go" with children's instruments and the sliced-and-diced version of newsmen Brian Williams and Lester Holt on "Rapper's Delight."
Each segment is funny, good-natured and utterly impossible to imagine Fallon's old-school predecessor doing.
"What I notice in people's reactions is not just that they like the show and think that it's funny, but they like the feel-good spirit," Harbert said. "There's a total absence of snarkiness, of cynicism. It's just there to make you feel good before you go to sleep."
The anti-show biz style pioneered by Letterman isn't dead, said Robert Thompson, director of the Bleier Center for Television and Popular Culture at Syracuse University. But "it may have run its course to some extent," he said, and Fallon's sincerity dilutes the pure snark of Letterman and O'Brien.
"Fallon has been able to change the equation," he said. He's made his mark despite a more crowded competitive landscape, with O'Brien, Jon Stewart, Stephen Colbert, Chelsea Handler and Arsenio Hall also mining late-night laughs.
During his first month, Fallon generated more than 120 million YouTube views, Twitter mentions and Facebook posts, the research firm RelishMIX said. That's more than double Kimmel, who had 57 million in the same social media metric. Letterman had 2.3 million.
"That lopsidedness is a huge wake-up call to writers, producers of late-night, network marketing departments and other series in all genres that they must 'feed the beast' or die," said Marc Karzen, RelishMIX spokesman.
Aggressive online exposure was a key part of NBC's launch strategy, which included timing Fallon's takeover to coincide with heavy viewer interest in the Winter Olympics, Harbert said. The next step is to find ways to make more money off all that online interest, he said.
Fallon's rivals haven't backed down from the competition. Kimmel got attention during the Winter Olympics for filming a stunt that jokingly suggested a wolf was roaming the halls of a dorm for athletes. With their youthful appeal (Fallon is 39, Kimmel 46), the two men seem primed for a bicoastal rivalry.
Letterman, during an appearance in January at Howard Stern's birthday bash, said Leno's departure wouldn't affect how long he wanted to keep working.
"I would do it forever if it were up to me," he said, before adding a wry aside: "Sometimes, it isn't up to me."
Judging by one of television's most prominent measuring sticks for likability, Fallon's success shouldn't be a surprise. He has a "Q" score of 19 among viewers aged 18 to 34 — which means 19 percent of people familiar with him consider Fallon one of their favorite personalities, said the company Marketing Evaluations Inc., which polled consumers both before and after the "Tonight" takeover. Kimmel's score was 16 and Letterman's 11, the company said (an average celebrity "Q" score is 17).