I'm going to yell:

BANNER ADS DON'T DO A DAMN THING UNLESS PEOPLE BUY THE PRODUCTS THAT ARE ADVERTISED. FROM WHAT I'VE SEEN, MUDCATTERS DON'T RESPOND TO THE ADS THAT ARE IN PLACE.

I, personally have found (and I suspect that Sandy at Folk-Legacy concurs)that Mudcatters are eager to suggest outside sources for recordings, although they're no cheaper and certainly don't do nearly as much for Mudcat.

THere are enough regular Mudcatters so that an annual income of a buck or so from each of them would support Mudcat and Digitrad just fine: sadly, there's no way at present to handle small transactions electronically. A cyber-turnstile would be great, but it doesn't exist.