The top mobile payment systems all work very similarly, but carry different fee structures. Each one charges a percentage per transaction and sometimes a flat fee per use. For example, mobile payment company Square charges 2.75% for a transaction that uses the swipe accessory. For transactions that are keyed in manually, Square charges 3.5% and a flat fee of $.15. PayAnywhere always charges a flat fee of $.19 per transaction but lowers its cut to 2.69% for swiped purchases and 3.4% for those keyed in manually.

Read more, via Detroit Free Press.