BARB. Though you may have to subscribe to find the exact figures you want.
I've found it almost impossible to find terrestrial and satellite viewing figures online although I know they are published. I managed to find some daily figures once and found one calculation for Discovery Science averaged about 40,000 an hour I think while Sky One got about ten times that. Some like Discovery Kids was in four figures and has since folded. But besides daily ones which I have not found since anyway is there anywhere with viewing figures for programmes as well?
BARB. Though you may have to subscribe to find the exact figures you want.
Digital Spy give a run down of some viewing figures for soaps/new shows. It's not much but interesting nonetheless.
Freddy
Ah, I think we've hit (literally) the bottom line. I did find a couple of sites offering viewing figures (no idea whether they'd show what I wanted to see anyway) but at a cost. Considering I am basically in a few programmes here and one in the States which has probably been pulled, a monthly or annual subscription just to possibly find a maximum of three numbers and never return is a very poor ratio. I did email one of the TV companies to ask directly once but you can imagine the response I got.
The only free site I found a few years ago only gave daily figures and no specific programmes and wouldn't be at all surprised if that's what I'd find for the minor channels if I paid for it. I'll look in digital spy though in case someone has a way in directly as it would be nice to know how many/few people have watched me.
Market research information is expensive to gather and rarely made available for free (why should it be?). Unfortunate if you only want a single piece of information but true. You could try the British Library or the BFI as they may have BARB subscriptions but I doubt if you're going to get the information for free on the net