According to analyst firm Superdata, Hearthstone isn't just a successful card game; it's massively profitable. With revenue gained from both the PC and mobile versions of the game, Hearthstone is bringing in approximately 20 million dollars per month.

In the report, analysts discuss what they believe has led to such incredible popularity: Hearthstone has followed the formula for success set by World by Warcraft. It combines deep mechanics with a level of accessibility that hasn't been seen before in the genre, all while capitalizing on the massively popular Warcraft franchise. This, combined with the ease of use thanks to an extremely effective version for both Apple and Android smartphones, has given players an exceptionally appealing starting point for CCGs, while also providing an outstanding experience for veterans of the genre.

Since the release of Hearthstone on mobile devices, PC revenue from the game has gone down, while mobile revenue has (obviously) shot up. This is, of course, due to more players spending time on their mobile devices, particularly (though this is speculative) when programs like Amazon's coins reward players for performing transactions through the Amazon App Store.

It should be stated that sales numbers are estimates based on a number of predictors, algorithms and hard numbers. With that said, according to Superdata's Sam Barberie, the company routinely back checks it's numbers and have found that the margin of error is usually in the single digits.

In a short amount of time, Hearthstone has put itself in a position where it is dominating the CCG market. This is certainly notable given its relative infancy compared to long-running games such as Magic: The Gathering, and can only make one wonder what the future holds for the genre.