[WARNING: This article contains ideas that may only interest people with elbow patches on their jackets. It often grossly oversimplifies esoteric concepts. As is usually the case when I'm grossly oversimplifying things, I don't care.]
Once upon a time, waaaay back in July 2006, there was a man. This man was upset with the current landscape of the used games market: he could either sell them for a lot of hassle but little money, or he could hope and pray that he could find someone to trade with. Neither of these were ideal. So he came up with an idea to facilitate game exchanges between like-minded gamers that avoided the normal downsides of other trading options. Thus, Goozex was born.
The man looked at his creation and saw that it was good. Trades were happening quickly. Concurrent trades were up to over 5,000. People seemed happy with the service, and he had a good system of monetization. It was, as Martha Stewart may have proclaimed, A Good Thing™.
But the man got greedy.