You can use this website for free CSGO Affiliate Gambling Codes or even to buy Gift cards.
What they do is:
They have a lot of users who uses their affiliate codes just to gamble for free and they earn a lot of money in csgo skins with them.
They use these skins to buy Gift Cards and sell back to their users at a discounted price as thanks for using their codes.
And that's how they cashout their csgo skins.
If you want to buy some gift cards at an awesome price check them out
CLICK HEREThey are online 24/7 if you need any help.