How about a new trade option: trade to be performed later.
Here's how it would work. You send one of your games "for trade" to someone listed as wanting the game in trade. In return, they agree to send one of their games (of equal value) off in trade to somone who wants it. Etc.
The geek would keep track of the trade chain, and overall "trade balance" for each participating trader. You'd probably not want to propose a trade with a player who already has a negative trade balance. Or you might favor proposing a trade with a player who has a positive balance.
You'd have the fun of watching the chain of happy people who all got something they want.