Everyone likes to get something for nothing.

Whether it's a hot breakfast with your hotel room, a car wash with an oil change or an order of fries with a hamburger, it's always satisfying to feel like you're on the receiving end of a good deal. A little something to sweeten the pot makes us feel good about spending a few bucks.

So let me ask you: How'd you like to get your hands on a billion-dollar business for absolutely nothing?

Zilch. Nada. Nichts. Don't worry. No strings attached. No salesman will visit your home.

How's this possible? It's not hard: All you need is a brokerage account.

The secret to finding these companies is to learn to love the balance sheet. Once you do, it won't take you long to figure out how to determine what a business is worth. The top part of the balance sheet lists the company's assets. The bottom lists liabilities. The third part is the (hopefully positive) difference between assets and liabilities. This is called shareholder equity or "book" value. If you sold all the assets and paid all the debts, book value is what would be left over.