I'd imagine the people buying promos, boosters, tcs, qi, and toriprime really help. Like I recently got Toriprime, and there are new people joining all the time who will probably eventually get it.
I wonder how much it costs to keep the servers running though. Totally clueless I am.
Surveys for sure...
I am REALLY glad this forum doesn't have ads. Makes it feel so much nicer than the ones that do, even if the ads are unobtrusive.
Oh yeah, lucky dip. Doesn't cost them anything to generate items!