meetdilip Well, it doesn't have to be "money" per se. Just some kind of points that indicate reputation (sort of like Stack Overflow or whatever). On the Fast Lane Forum I mentioned as an example, the points are displayed as USD, but are really just points.
Reputation Transfer on that forum actually allows a person to give earned points to another user in any amount(!). As I said, I am not sure this is a good idea for overall forum health, but it does allow some interesting interaction on that forum that I have not seen on any other.
What I am personally working on is a set of Ethereum Solidity contracts that tie to the Vanilla forum API so that this might involve actual spendable currency. If I can get it to work, I will try to get it to work for Flarum as well, since I actually like Flarum better than Vanilla...