I saw last night that NBC is moving 'Scrubs' back an hour, so that it will now be shown at 8:30 on Thursdays. Additionally, they have moved '30 Rock' to 9:30, basically switching the time slot of each show.

Now, if I remember correctly, moving a show back an entire hour is a sure-fire way to lose a good portion of its audience. I know they did it halfway through the second season of Carnivale, and, well, that also turned out to be the last season. I also think that moving a show up an entire hour is often used as means to boost ratings.

So, this makes me wonder: did NBC move Scrubs up in the line-up because it was doing poorly? It's a popular show that's well into its 7th season, so it's clearly profitable. Maybe it's not doing as well as usual, so they network wants to rectify that by putting it on a little earlier? If so, then they're doing it at the expense of 30 Rock, which has only been running for about a season and a half. It's also critically acclaimed, which probably means it doesn't do so well ratings-wise.

Is that right? Do I have this completely backwards?