MB this has been approached already, but I couldn't find it on the forums.
What happens when we reach maximum allocation of BitCoins?
Currently there are about 6m coins in circulation. I believe the maximum is 21m. I don't know the rate of creation, but I read somewhere than theoretically in 50 years time all the coins that can ever be created will be in circulation.
Question is: What then
At the moment, the nodes supporting the network are incentivised because they get paid a certain amount of coins per transaction, which they are allowed to create.
However when #BTC = 21m, nodes will not be allowed to create any more BTC.
So what incentives are there at that point for nodes to continue supporting the system?
Fees.