This chart, via OnMyOwnTwoFeet, shows the incredible costs if you incur $5,000 in credit card debt and only make the monthly minimum payments. By the time the debt is paid off, you’ll have effectively paid double the original debt.
This is why it’s 1) really good to pay your credit off in full every month and 2) if you can’t do that, pay as much as possible, and definitely more than the minimum monthly payment. These payments are purposely set low to keep you in debt as long as the credit card company can. It’s called the profit motive, and it’s not just for corporations, you should apply it to your personal finances as well.