In-game micro-transactions as involvement devices?

Could the in-game micro-transaction model be applied to non-game websites as way to draw donation money out of users without hitting them up for money? It seems as though a game type model would have to be employed to encourage people to participate in systems that accrued rank, badges, points, etc, and had tangible payoffs for investments of time and money.

TwoFish Announces Micro-Transaction Engine for Games

I wonder if this could also be translated into a user immersion strategy for campaign or other donation driven websites. The question is, what do you hold out as the carrot to site users in a non-game environment? Pay for content models have been tried with limited success. Would you have to create a game like experience and community in order to facilitate a pay as you browse model?