If it's anything more than free I'm sure not going to use it for something like paying a bill or getting coffee. My banks debit card doesn't charge me to do that.
If it's a negligible amount like 1 cent then people will think of it as free. Once it rises above a few cents people will choose to use free methods of payment like debit cars. The only case where people might be prepared to pay high fees is sending money abroad when the fees are less than the fees for wiring money between bank accounts.