You probably figured Diablo III sales were huge, but not this huge: the game sold 3.5 million copies within 24 hours of launch, making it the fastest selling PC game of all time. Still think the platform is dying?
An additional 1.2 million played the game via the World of Warcraft Annual Pass promo, totaling nearly five million people. A week later, over six million are playing, excluding players in Korean "game rooms", where the game is a huge hit.
So, despite the always on requirement and the consistent bitching of many fans online, it appears barely a dent has been made in hard sales numbers.