Mr. Leno had 18.4 million viewers last night, which proves…uh, not very much. Tonight, he'll probably have less than half of that and by the end of next week, we should have a pretty good idea where the numbers are going to settle in, at least for a while. NBC is surely happy with the total viewership last night, though a little disappointed at the demographics, which skewed older. Oddly enough, Conan O'Brien's ratings were up due to older viewers but he finished lower than usual with the 18-34 audience.
The success or failure of The Jay Leno Show is going to be a difficult thing to assess, because it will not wholly be about the ratings on his show. NBC is going to have to look at what he's delivering in terms of lead-in to the local news broadcasts that follow him all over the country. If they take a plunge, that won't bode well for Jay even if his numbers are okay. Likewise, NBC won't be thrilled if Jay does well but Conan seems to be hurt. Someone's probably going to do some sort of polling and statistical analysis to determine if The Jay Leno Show at 10 PM prompts more folks to go to bed earlier.