Does GOG even have a friends list?
They do? You can trade other game cards or a whole bunch of other tradeable stuff that Valve games give you for free for just playing games. And if all else fails, you can buy them in the community market with free money you get by selling a whole bunch of useless shit Valve also gives you.
Quoting but I took none of the keys
My problem with the trading at the moment is that like others have said, if you want to craft the badges you wind up in a situation where you have literally zero fodder to trade with. I need to keep the cards I have since if I trade them away I'm going to have to buy them off the market again anyways.
The coupons, backgrounds, emoticons value for significantly less than what it takes to craft them, and steam does not facilitate the trading of giftable games on the market, not that it's even easy to find someone willing to trade for a game in it's equivalent worth in cards. I have zero interest in grinding tf2 for hours a day just to get metal for cards at that, I have time and a million other games to be playing (yes, I play my steam games)