ytswy - 4:37 pm on Jan 24, 2012 (gmt 0)
sun818 touched upon debit cards. I'm assuming that this discussion is about the US, and I'm not sure how it differs from the UK, but while we pay a little over 2% for credit card transactions, we pay a fixed rate (about 25p) for debit cards. For large transactions this can be a very significant saving - paying 25p rather than £50 on a £2500 order makes a difference.
Debit cards are very widely used in the UK (Visa Debit accounts for well over half our transactions).
I seem to remember a few years ago reading here that there was a stigma attached to debit cards in the US - they were seen as something that was only used by people who couldn't get a credit card - whereas in the UK using a debit card means "I actually have money in my bank account". Not sure if that is still the case, but you might want to discourage the view if it is...