If you sell items for $5 and the card charges e.g. 2.9% + $0.30, that's >11%. On top of that, merchants carry the risk of chargeback fraud or stolen cards, and

If you sell items for $5 and the card charges e.g. 2.9% + $0.30, that's >11%. On top of that, merchants carry the risk of chargeback fraud or stolen cards, and in some industries that can be another double digit percentage by itself.