Perhaps per-channel sponsors make sense. Cooking, Tech, etc..these are established niches/demopraphics. (metamucil / robot insurance ads on the classic movie channels)

I think distributing power such as banning sure helps to propagate community norms. An example: the 'intellegent design' spammer getting his ass bounced. Distributing power seems to scale up well and resist most attacks.

All hail Siftbot!