They're a great way to trade games off. I have five items up on the list right now. I kinda prefer math trades because I don't have to find somebody who not only wants my game, but has something I want in return. This way as long as somebody wants your game, and you want somebody else's, there's a chance the trade will go through.
Thanks. I've not done a math trade before so I would have to read up on the procedures...but now might be a good time to learn.