I agree with Rhytania, though to be honest I'ma be considered broke for at least a few months.
Adwords are alright, but I don't find them exceptionally useful. I see them, but unless they're explicitly relevant to my search (and sometimes even if they are), I ignore them.
TMC, I feel, IS the best option for advertising. I dunno if there's a way to increase visibility in zMUD/CMUD, but that's a thought.
My only concern would be increased suspicion of favoritism. It could be seen as donators are seen more valuable and thus likely to receive additional benefits (though _I_ wouldn't see it as that at this point). Especially, perhaps, to newer players coming in. Maybe if there was a way that all donations were made anonymously that they couldn't possibly make such claims?
In any case, I'm all for more visibility. We do have a devoted staff, regardless of whether I agree with some decisions. We've got a great playerbase who is very conscious of their affects on the MUD as a whole. We've got new players who are showing a nice measure of interest and enthusiasm. We've consistently got D&D-aligning changes that further increase our foothold on such a diverse group we want to attract.
In my opinion, FK deserves such visibility. Not out of desperation, but because it's that much better than our competitors (I feel, anyhow). Why not give it a shot?
This land shall come to the God who knows the answer to War. -Ninety-Nine Nights