I think lead in's go like this: I like to watch the Office on NBC. Show finishes and I look to see what there airing next. If the show if the show is crappy (i.e Jay Leno Show) I change the channel, if it's good I stay with it most likely all the way to late night TV (Conan). In other news... Last night's episode of "Tonight" had a 42% ratings surge, beating Letterman. Not really suprising since people want to see what Conan has to say. Leno's ratings were flat. Also Leno himself may be considering leaving NBC from a rumor I read.