That is somewhat close to the idea of using something akin to the karma system of slashdot. Both for post and upvote/downvote. It comes with various reasons (tags) for upvote downvote, and gives feedback, as well as affecting the mechanics. Perhaps ways to upvote without giving money, or affecting the SP/SD ratio that this particular vote gives (or how the author prefers their reward). Will have to think about mathematical implications for such a change, of course, but I consider something like that worthwhile. Maybe even being able to specify the recepients of the reward, so that agregated posts could automate the payout for the authors they feature.