Would that work for non-life-saving medicine? I'm thinking of dietary programs, specifically. With everybody and their brother offering "new, revolutionary fat loss techniques" I'd be surprised if nobody ever tried a micropayment system.

(Something similar I do is offering myself alternative rewards for my good behaviour - when I really crave some ice-cream, I decide I will treat myself to a new toy/book/clothing item/etc. if I manage to abstain. Doesn't really work if it's raining, unfortunately.)