I can't remember if referral links are allowed or not.
Anywho G2A isn't an authorized reseller for any games, if you get a key it's not guaranteed to work since there is no way to check if you got a used key. They can send you another key, wouldn't be surprised if you had to pay them more since that's what these type of sites do if they do think you're telling the truth.
All these (unathuarized) CD Keys site are scummy too. The reason their prices are so low is because they buy games in places like Russia and Asia where games are cheaper, and they even buy games from bundles to sell them at a higher price individually which is just a shitty thing to do. These sites also get linked to stolen credit cards.
[Image: http://puu.sh/97MA9/0085911c85.png]
Honestly avoid sites like these