How about every member has a gallery limit of 12 or 24 submissions. When they reach the limit they have to delete something to post another. I know some people feel they need to post 3 Victorias with blank stares a day, that can be done as long as they have 3 empty slots. As for getting that member's last dollar in Renderosity's pocket, charge for extra gallery pages. Say everybody starts with 12, and charge whatever for extra pages of 12 or such. The crap will still flow steady, but at least it won't get all piled up as much.