What if I told you there's a potential $100,000 smackaroos in it for you for just sticking with me for another three minutes?

Here's how: Clean up your credit score.

Seriously, I'm not going to harp on about how stellar credit means paying less interest on loans, qualifying for lower insurance premiums, and sailing through things like landlord and employment background checks. You know that already.

Instead, I'm going to let cold hard cash do the talking.

The table below illustrates the difference between what someone with a good credit score (e.g. 720 and above using the FICO scoring system) and someone with poor credit (less than 620) pays over the course of 30 years on a $150,000 mortgage. See for yourself:

Payment Schedule for a $150,000 30-Year Fixed Mortgage

Credit Score


Monthly Payments

Total Interest Paid





















Source: preferredcreditsolutions.com. Example based on historical mortgage rates.

Every single month, the person with poor credit pays $278 more than the neighbor with better credit for the exact same mortgage. Month after month of being saddled with the higher interest rate adds up, and after 30 years the difference comes to a whopping $100,069.

The damage -- and savings -- runs even deeper
Now imagine how much more money you're passing up by being passive about your credit score. Every car loan, credit card rate, and maybe even insurance premium is tied to your credit score.

Poor credit adds more than $6,500 to a 60-month, $25,000 car loan -- that's $100 a month more than the driver who cleaned up their credit before car shopping. Got a credit score that's less than 550? Be prepared to shell out $600 more a year for your car and homeowners insurance than if your score was 750 or higher.

The lesson here is pretty clear: Spruce up your credit and start saving some serious cash.

See how you rate starting right now -- and for free!
If you've got a secure Internet connection and don't mind sharing your Social Security number online, a rundown of all your credit deeds (and any misdeeds) as well as your credit score are just moments away -- and for free, even.

Pull your credit files: To see where you stand, head to annualcreditreport.com (or if you're more comfortable doing this offline, call 877-322-8228) to get your Equifax, TransUnion, and Experian credit reports for free once a year.

If you haven't reviewed your credit files lately -- or ever -- pull all three at once to get the full picture of your credit reputation. Creditors don't always provide data to all three bureaus, so you can't assume that what's in one of your files is the same in all three. You can also spread out your freebie requests over the course of the calendar year to keep an eye out for any funny business.

Check your credit score: I know you're itching to see where you stand, and CreditKarma.com offers instant gratification -- a free credit score without the gotchas that make other "free" score offers a pain (like the product trial you have to remember to cancel). The company makes its money by letting partners pitch their products to you on your results page.

The score is generated by TransUnion and translated into the standard FICO range of 300 to 850. (Note: There are many kinds of scores:  FICO, VantageScore, EMPIRICA, BEACON, etc. The important thing is to know where you rate on the general scale of atrocious to awesome, and to aim for awesome.)

By the way, checking your own score does not ding your credit -- it's called a "soft" inquiry, which is like window-shopping at the mall without a wallet. A "hard inquiry" indicates you mean business -- that you're trying to close a deal and have authorized a lender to check you out. A few such inquiries a year won't hurt your score.

Shape up your credit and start saving
If you've done some less-than-stellar things in the past with your credit, don't fret. There's plenty you can do to improve your credit reputation. Read on:

Dayana Yochim has nothing in her credit report to be ashamed of. Thankfully, no one compiles fashion files or the '80s would still be haunting her file. The Fool has a disclosure policy.