In order to fully understand credit card rates, you have to keep the following seven credit card fundamentals in mind:

1. Corporate Office vs. Used Car Lot

If you had to picture the average employee at your credit card company, what type of individual do you imagine? Is it a professional in a suit? If so, you'd better change that perception in order to understand the world of credit card rates.

Think of the credit card company as a used car lot -- they want to razzle you and dazzle you with low credit card rates in one hand and then pile on the hidden charges with the other hand when you're not looking.

2. The Rate May Not Be Set In Stone

When it comes to credit card rates, the interest you pay in the beginning may not be set in stone -- especially if that interest rate is exceptionally low. Let's face it, the credit card companies are in the business to make money.

If they charge you 0-percent interest for the life of your account, they aren't going to make a dime. If they charge you 4-percent interest for the life of your account, they're not going to make enough to be happy.

When a credit card rate starts out very low, it goes up eventually. Read the entire credit card agreement so you know exactly how much you'll be paying, and when.

3. Somebody's Watching You

The world of credit card rates is like a web. The credit card rates you get from Company A, B and C do depend on how you pay your bills with company D.

How so? Because of the notorious universal default clause. Basically, this part of your credit card agreement (and your agreement does indeed have this clause) states that if you pay any of your bills late and the credit card company finds out about it, they can hike your interest rate skyward -- regardless of your payment history with them.

4. They're Not The Be-All, End-All

If you shop for credit cards based on credit card rates alone, you're doing something wrong. Unless you carry a high balance on your credit cards, there are other factors you should consider when selecting the one that's right for you. Things like cash-back awards and other credit card perks should be considered -- especially if you pay your balance in full each month.

5. It Adds Up Over Time

The biggest mistake people with low credit card rates make is thinking they can charge up a large amount of debt because they're paying it off at a low interest rate. Remember, no matter how low your credit card rates are, it's still cash out of your pocket and over time the amount can add up.

6. Credit Card Rates Can (and do) Change

Even if you pay your bills on time each and every month -- even if your credit gets better and better -- your credit card rates can still go up.

Why? Because credit card rates are not necessarily fixed rates.

If the bank's cost of borrowing increases or if the bank merges with another bank (which is not uncommon), your interest rate may take a hike.

If you carry a high balance on your credit cards, changes to your credit card rates can end up costing you a pretty penny. Because of this, it's always wise to keep your credit card debt as low as possible.

7. Three Words to Remember

The final fundamental I would like to leave you with in regards to credit card rates comes down to three little words (and they're not "I Love You").

What are these three magic words? "Lower my rate."

Yes, you read that right. If you think your credit card company is charging unreasonable credit card rates, call them up and tell them you want them to lower your rate or you'll transfer the balance elsewhere.

If your credit is in good standing, you may actually get your wish. Remember, credit card rates (like most things in life) are negotiable.