Well, they couldn't do SotL unless they can get the rights to Clarice Starling, who is apparently bound up by MGM. Don't ask me why they can use other characters from the books but not her. But yeah, that's far in the future.

I don't really know much about ratings, either. But Wikipedia does list them as down from the first two episodes. Maybe we'll at least get two seasons? It keeps getting good reviews.

NBC isn't doing well, though, lol. They don't really have any hit shows at this point. So it's not really a matter of it not being one of their high performing shows, because they don't have any. Well, there's reality TV of course. But NBC is fifth in the ratings according to the sweeps reports, which is bad for them because they're one of our three big networks, and obviously one of the free networks.