When you’re looking to buy a home, your real-estate agent may suggest you see a mortgage broker. What are mortgage brokers and what do they have to offer? Well, a mortgage broker is someone who shops around from bank to bank and tries to find the best mortgage for you.

Sounds great, no? Well, they can be, but nobody does anything for free. While you often don’t have to pay a mortgage broker anything out of your own pocket, the broker does make money off of your loan, in the form of rebates or commissions from the bank and built-in fees.

Sometimes that works out fine, since the broker is going to find you such a kick-ass loan that, even with the fees and rebates, it’s still a better deal than what you’d find on your own. Another reason brokers can be useful is if you have lousy credit—they can find lenders who won’t laugh the moment they see your FICO score.

Of course, getting a broker isn’t the only way to go about getting a mortgage. You might find a better loan yourself, or through a deal your employer has with a bank. Bottom line: You’re not obligated to get a loan from a mortgage broker who has offered to try and help you. So you might as well have one shop around for you, but you should also do some research on your own. Whoever finds the best mortgage wins.