I think for trading to be successful in CS:GO, if that's what valve wants...
And for a trading server to be successful...there needs to be an in-game trading feature.
As I understand it right now, you have to add someone on steam to trade?
But in TF2, you just click a button, trade someone in the server and it's all done in-game.
Now, I'm not saying this should be added into the game..
It would completely ruin the game even more than what has already been a ruined CS game.
But maybe if it was implemented, there should be some kind of server side option to disable it for actual game-mode servers.