As long as you have your debit card, it is more than enough, with the credit card there are charges.

I remember CBQ, was promoting a WOW credit card a few years back, no charges, no strings, however, the problem/string was, you cannot pay back the full amount spent, only 75% and you pay interest on the balance throughout, so you were stuck in a loop.
Banks are same as any other business, that is how they make their profits.