I've been playing TF2 for a long time, since Dec 13, 2008 according to my TF2 medal, and I have gotten loads and loads of weapons since they added the feature with nothing to do with them. I often found myself going back to the original default weapons since the game is balanced regardless and I still did just as well with them as I did with the new stuff valve was releasing.
Then came along Steam Trading, and not only from peer to peer for TF2 items but for games as well. To make this story short, I got five games, FREE OF CHARGE, for weapons and hats I recieved while playing a game I would have played for this long anyways.
The five games where:
(These were all games I wanted by the way... I know it's weird I like indie games...)
I assume someone will point out the obvious fact that with that time I spent playing TF2, if I had instead gotten a minimum wage job I could have bought a car by now. Let alone buy the $18 worth of games you see up there. But that fact is I was going to play this much TF2 anyways, and now I have 5 games for nothing but doing what I would have done. I turned a sick amount of gameplay time with a single game into something that costs money, and that is pretty cool to me :)
I will be very interested to see what I can get with more tf2 items in the future, whether or not DOTA 2 will also have items to trade with, and of course Diablo 3's real money auction house... this is a weird time for video games eh ? But exciting none the less.