Best way to hurt Mastercard and Visa: pay with cash whenever you can

The alternative, cash, cheques, and debit cards, are just so inconvenient. My bank absolutely takes me to the cleaners for fees when I use my debit card and cheques, not to mention the hassle of actually having a chequebook handy.

I really dislike carrying cash, too. Several months ago I had my locker broken into at the swimming pool and had around $100 stolen from my wallet. It was easy enough to cancel my credit cards, have any unauthorized charges reversed, and have them re-issued, but the cash was as good as gone.

And mail order without credit cards? Forget it!

OR use any other credit card (AMEX, Diners Club etc.) to bring profit down of visa and mc ..

Or just pay your bill when it comes so you don't pay them interests

They still take a cut from the merchants for each transaction--though it's a good start, and living debt free is great.