Also , the economics of the bitcoin system require that a fee market develop over time as the block subsidy decreases . The requirement for a fee market doesn ' t follow from this . All that ' s required is that the total value of fees paid is enough to incentivize miners to provide an adequate level of security for the blockchain . This can also be achieved by simply setting a minimum fee requirement , however low that turns out to be . Admittedly this requires some level of consensus regarding what this minimum fee should be , and a fee market might be a superior mechanism to arrive at that value . But it ' s not an absolute requirement to have a fee market . <| sep |> In my hometown , someone successfully used a fake $ 200 bill at the Dairy Queen and got ~$ 190 in change .