I will just finish that thought.
I have friends who work at banks. They're all bank managers. Among the credit cards, checking accounts and savings accounts offered, it's the ones that are more high-end—they have a higher fee or ask you to hold more money in a bank account—where Interac is free.
Some of the lower accounts, the starter accounts—the ones where you don't have to hold a certain amount of money in your account, maybe because you don't have that money—are usually the ones that will charge you for Interac service.