If you’re unfamiliar with how skin gambling works in Team Fortress 2 it’s basically a Counter-Strike: Global Offensive clone made by Valve. They have released the following statement recently:
“In July of last year we outlined our position on gambling web sites, specifically noting that Valve has no business relationship with these sites. At that time we also began blocking many CS:GO gambling accounts… More recently, some gambling web sites started leveraging TF2 items. Today we began the process of blocking TF2 gambling accounts as well. We recommend you don’t trade with these sites.”
We can’t really blame them, can we? It’s a business and they don’t like it. So if you’re using some kind of TF2 gambling/trading websites it’s your last chance to get something that you really want.
Source: PC Gamer