One of the points made in this ridiculously superior Babble article:
http://www.babble.com/kid/kids-learning/no-santa-claus-for-our-kids/
is that telling kids to be good because otherwise Santa won't come is "extrinsic motivation", and that's bad.
So. I'm just wondering how many people go to work or clean their house or whatever because they just feel they SHOULD, and not because they get paid, or get a clean house and spousal approbation and respect, or, you know, all those other EVIL extrinsic motivators.
Human beings don't do anything without a reward. Even giving without receiving, as the author goes on to imply is the exclusive province of non-Santa kids, makes us feel good. That feeling is a motivator. Santa's no different from the threat of punishment for bad behavior, except that - as with all other humans - positive reinforcement and rewards are always a better motivator!