And it's not like it's completely volunteer - we're working on the game in the hopes that we can finish it, sell it, and get moneys. For right now, it's volunteer, but it's not completely altruistic volunteerism.
If nothing else, though, the being known part is a good incentive - if he can put us on a resume and say "hey, didn't finish the game with them, but I did these artworks for it", then everybody still wins.