If next month's balance is again not paid in full, that month's additional interest plus your previous unpaid interest is carried over into the third month. Once you understand this concept, it is easy to forecast how your debt will continue to grow month after month, year after year, until you take steps to halt the debt cycle.

As if this is not depressing enough, credit card companies love fees. Every time a fee is capped or eliminated or otherwise modified by state or federal financial service and industry regulators, all those clever credit card companies come up with a new one or a workaround.

Again, this means the amount of money you owe is increased. Late fees are common, as are fees for exceeding your credit limit. Some card issuers will charge you an annual fee for the "privilege" of using their card. It is not unusual for these fees to be $30 or $40 or even $50 per year. This charge is of course rolled right into your outstanding balance. Here are six other types of fees that you might encounter during your dealings with the issuers of credit cards. None of them are pretty.

• Reward Redemption Fees. Just because a company calls something a reward doesn't mean that it is free. Airlines were among the first to pioneer this concept with regard to using or cashing in frequent flyer miles. Perhaps the best known example is the hefty fees that you are charged for purchasing or changing airline tickets. Credit card companies may get a piece of this action.
• Foreign Transaction Fees. If you only use your credit cards within the U.S., you might now be aware of these nuisance charges. Formerly known as currency conversion fees to cover the cost of changing dollars into foreign currency, know even dollar-for-dollar transactions may be subject to these charges. These fees are usually a percentage of the total transaction cost. To add insult to injury, your bank might also add an additional fee to this one.
• Reward Recovery Fees. Reward points for your use of specific credit cards may be revoked or frozen if you make a late payment. When they're gone, they're gone for good and there is no way to recoup them. These fees are rarely imposed, but they do exist and can be located in the fine print of your credit card agreement.
• Activity Fees. Keeping an active credit card in your pocket and not using it on a regular or periodic basis can result in a fee charge for inactivity. At least one credit card company will impose a $60 charge if your annual transactions fall short of their designated amount, although it might be refunded once that amount is reached or exceeded.
• Payment Protection Fees. These can be a gold mine for card issuers. If you are unable to work or otherwise unable to make a regular monthly payment due to a special hardship, the card issuer will cover this missed payment or payments if you pony up a fee for each $100 of your outstanding balance. At 80 or 90 cents or even as much as $1.00 per $100, this can add up fast. And as you would expect, this sum is rolled into your outstanding balance.
• Paper Statement Fees. Just as many banks have stopped providing people with personal checks that have been processed, a few are testing the idea of charging a fee for the processing and mailing of monthly statements. The fee would be directly debited from your checking account.