"For the record, MOST online payment processors have been treating debit card transactions like credit card transactions, and therefore charge the higher interc

"For the record, MOST online payment processors have been treating debit card transactions like credit card transactions, and therefore charge the higher interchange -- even when they have no legal right to do so." Erm, you are aware that lower interchange fees for debit cards used at point-of-sale is because users have to type in a PIN on a (nominally) secure terminal? That reduces fraud risk, so the rate is lower. Most payment UIs don't prompt for PIN, so they don't get the rate. Tighten down your tinfoil hat before typing next time. (full disclosure: I'm a developer at a payment processor)