I started out promoting the bigger programs, and still do if a fave sponsor brings out a new one - but the smaller ones are definitely the way I'm heading now, CCBill is great since you don't have to wait to hit minimum payments if you're only getting sales here & there
Plus I'm finding a lot of better niche-specific sites with smaller sponsors, which of course sell better long term.
I guess a mix of both is good, some surfers like getting a big variety.
Ponygirl