After any update if any parameters of your sets changed/nerfed, u get a possibility to trade this set to some sort of tickets. Theese tickets u can trade for anything, idk what exactly. Gold items can be traded for much large amounts of tickets, than violet/blue/green quality items. It would be a little compensation for your time or/and money, which u spent to get a items/set ruined after update. I am just tired, cus spent so many gold and time to make build which was totally ruined after one of the patches.