The ratings from "Conan's" debut episode.
During last night's bow on TBS, "Conan" pulled in 4.2 million viewers, many of whom are on the younger side of adulthood. The projected median age for last night's audience is 30, with 2.4 million viewers falling in the 18-34 age range.
Meanwhile, O'Brien's old gig, "The Tonight Show," drew 3.5 million viewers, while "The Late Show with David Letterman" attracted 3.4 million, according to the Hollywood Reporter.