I wanted to get a Fancy Dress Uniform for soldier in TF2 and to my surprise, I found that not only my Engie Teddy wasn't good enough, but that there are sites dedicated to tell me how much my stuff is worth. It's like the stock market, but for kids with too much spare time and perhaps, low allowance.

Unless you are trading with friends, it's just simpler and quicker to buy whatever you want on the store (or craft it with spare metal) instead of trading because they take their virtual goods seriously and they need to get an edge on you.

People will go to great lengths to maximize their "profits" in TF2 right now. They trade 1 for 2, 2 for 3 and slowly build their hat-based wealth.

Later they will brag about how they managed to buy indie games on sale with the fortune they acquired trading headwear.

This, my friends, is the market of the future.

Invest now.