You're right about the general case; a restaurant running two $50 payments or one $100 payment usually won't see any difference. But a thousand $1 micropayments produce more overhead (and more risk) than one $1000 payment, so below some threshold it's not worth handling them. As a result, most card processors have rules to either block that payment pattern or raise costs on it.
Common approaches include:
- Caps on monthly transaction counts
- Caps on monthly payment amounts, with usage monthly fees
- Flat costs added to percentage fees
- Percentage fees with a minimum charge
Similarly businesses which know they'll see numerous small payments mostly just charge enormously high fees. The Apple Store and Google Play both take 30% transaction costs, and I suspect they pay their processors noticeably more than the common ~%2 rate despite their size.
Common approaches include:
- Caps on monthly transaction counts
- Caps on monthly payment amounts, with usage monthly fees
- Flat costs added to percentage fees
- Percentage fees with a minimum charge
Similarly businesses which know they'll see numerous small payments mostly just charge enormously high fees. The Apple Store and Google Play both take 30% transaction costs, and I suspect they pay their processors noticeably more than the common ~%2 rate despite their size.