I never or rarely use cash, and use my Aeroplan card for every purchase, be it for coffee, to pay municipal taxes, or a plane ticket. I also get to use it occasionally for work (charged $4,000 of hotel rooms last week for a board meeting). I've been paying the balance in full every month since I've had a credit card, and never paid a cent of interest. This card usually gives me about 60,000 Aeroplan miles per year, enough for a roundtrip to Europe. However, one must be very diligent about paying the whole balance in order to benefit from reward cards, but if you have a tendency not to pay your bills on time, using cash is the best option to avoid the so-common credit card trap.