"The incentive can also be funded with transaction fees. If the output value of a transaction is less than its input value, the difference is a transaction fee

"The incentive can also be funded with transaction fees. If the output value of a transaction is less than its input value, the difference is a transaction fee that is added to the incentive value of the block containing the transaction. Once a predetermined number of coins have entered circulation, the incentive can transition entirely to transaction fees and be completely inflation free." http://nakamotoinstitute.org/bitcoin/ http://nakamotoinstitute.org/bitcoin/