They aren't handing you money. When you buy shares you are buying a part of the worth of a company. When the spin off happens you will keep all the shares of the original company but the companies worth will change. They will then issue you shares of the new company based on the worth taken from the original company. Now things can go a few ways. The original company could grow and become worth more and you make money or the original could stay the same or become worthless. Hard to say. Same goes for the new company. If they both go up, you make twice as much. If they go down.. Well.. Gambling sucks sometimes..