G2A always has 10% discount codes that work with most items, there's even a 10% code that works with Steam/Playstation/Xbox gift cards (TERRITREVIVAL10) and a 15% code for games if you buy in the app (WINTER15). I was wondering if there's any deeper reason for not showing these in the site, specially the gift card one since it makes G2A the best choice for pretty much all gift cards.
Proof of discount working: 
