I think that's the key. I won't use a debit card for purchases. I use a credit card (paid in full each month) for most purchases, and cash or check (fewer and fewer) for the rest.
Why no debit card? It started because debit cards didn't have the protections of credit cards, but also I just don't like the idea of vendors being able to reach into my bank account, even through a third party. Actually, my card is a combo debit credit/credit card, I sometimes use the two terms interchangdably.
I've been with the same banking institution since 1992 (Meridian-Core States-First Union-Wachovia-and of course, now they'll be Wells Fargo) and I get a few nice benefits for being with them that long.