I am not one to jump into these type of debates anymore but this statement just misses the fundamental point of what people find wrong with grey market sites. Its not a matter of whether the keys work or not, it’s a matter of where the keys are sourced from.
Now I am not saying that all keys on those sites are illegitimate or stolen keys, but certainly not all of the keys are obtained legally and the fact that they facilitate that or a person may obtain one of these ill gotten keys is not something many are ok with (hence why is there any deal does not include those prices in their lists) as that tends to hurt the developers and the game industry in general. They are called grey market sites for a reason, legal but not necessarily legitimate or ethical.
And if you don’t believe my statements just the other day one of these sites had to make good on a claim that if anyone could prove that they sold stolen keys they would pay tenfold the amount that the developer lost.
As a general note to everyone here, if you purchase from these sites that is your prerogative, but no promotion of any ‘grey’ market sites are allowed on these forums, any links and at minimum your post will be removed and further action will be taken if necessary.