Gifts that keep on givin

We're having an office Christmas party and someone came up with the great idea of exchanging gifts. Whoever that was also set the max amount of money you can spend at $20. That's a buttload of money for a college student!!! So then they figured we would make a list of a few examples of what we want for Christmas...and almost everyone is putting down gift certificates. I don't understand gift certificates. If I'm just gonna use it to buy what I want anyway, why don't I just save you the trouble. You keep your money and I'll keep mine, then I'll go buy something I really want and say, "hey, look what ______ gave me for Christmas!" Now that's fun.