Use your credit card, earn over $70,000.

How you may ask? No, it’s not some scheme. Credit cards are often criticized for their high interest rates and exorbitant late fees. However, if you work the system properly, you can make money for something you use anyway.

First question to ask yourself: Do you pay off your balance in full every month? For this to work, you must pay off your balance every month, otherwise, any potential benefit is offset by the interest you’ll pay. Second question, does your credit card offer a cash reward? If not, why not? There’s a pretty good selection of credit cards that offer anywhere from 1-5% cash back, depending on what you buy and your level of annual spending. This is all with no annual fee. American Express Blue Cash, Citibank Dividend, and Chase Freedom are a few that I like.

Let’s assume that you spend $20,000 a year on your credit card. That means, you'd get a $200 refund every year (assuming 1% cash back). So here’s what you do. Take the money that you get back from your credit card company and invest it, don’t spend it. (It’s hard, I know.) Invest that into an IRA (Roth if you prefer). If you start at age 30 and do that every year until you retire, that’s approximately 37 years you invest $200 a year. Assuming you earn an average rate of 10% over that time, that $200 every year will turn into $72,609 by the time you retire. Not bad, for something that you use anyway, right? You’re that much closer to your first million.

Any other ideas out there?