The Hoarder is a good example, and though I wasn't conscious of it at the time was clearly one of the inspirations for my version of the move - at the beginning of the session, there's a roll to determine the hoard's "hunger" for that session, which gives the MC hold that he or she can use to put the Hoarder in a difficult position. But the PC can also do things to reduce (or increase!) the hoard's hunger, so both the MC and the player are active participants. And really, the need to feed to hoard is a compulsion, much like "greed" might be. In terms of incentives, the hoard's hunger is good because as soon as the MC names a thing that the hoard must have, it gives the player the opportunities for hilarity and mayhem (and experience, because the Hoarder is almost certainly going to be rolling highlighted stats in the process).