Why are people here so quick to judge GMG?
Where have they actually said they are an authorised dealer of EA, Ubi, Acti etc.? They might have said it in the past, but it looks like they've taken EA and Ubi and Acti logos from their website. If that's the case, they are getting their keys from elsewhere.
If you buy a key from GMG and it doesn't work, as long as you can get a refund, then is there really problem here? As long as its not stolen either, which by all accounts GMG have been pretty legit since they started.
The way I see it, EA, Ubi and Acti were offering them a tiny percentage of the sales, EA, Ubi and Acti basically hold all the power here as they have their own webstores and online portals for gamers. At the same time, EA, Ubi and Acti also offer backdoor deals to smaller distributors and wholesale buyers to move even more units. From a business standpoint, GMG are taking the route with higher profits by buying from these wholesalers. It's like the most obvious option isn't it? If EA is offering you a wholesale price of $58 on Battlefront but the wholesaler can offer $45, its a no contest.