[bitsm]

Forrst has a similar system for promoting user posts as an advertising alternative, though Kyle (founder) uses credits (called acorns) and there are several ways to earn credits, outside of simply purchasing them.

It's a great idea: it's hard to get more "targeted" with ads than content that would have been posted within the community anyway.

If anecdotal evidence is any guide, it seems to have been received really well within Forrst, and the backlog was huge the last time I looked (not enough pageviews to match demand).