there's also a flat fee per transaction (eg, 3.25% + $0.10). this can make the effective rate pretty high for small purchases. https://www.valuepenguin.com/cre

there's also a flat fee per transaction (eg, 3.25% + $0.10). this can make the effective rate pretty high for small purchases. https://www.valuepenguin.com/credit-card-processing/interchange-fees https://www.valuepenguin.com/credit-card-processing/intercha...