The game launched on iPad in April 2014, but Hearthstone‘s mobile revenue had remained relatively low until the turn of the year. With the launch of the phone version of the game, mobile revenue has increased from around $2 million to over $10 million. In contrast, PC revenue has dropped from close to $15 million to nearer $6 million.
The contrasting fortunes give plenty of scope for conjecture about where people are playing Hearthstone, but it does seem to suggest that a large part of the game’s existing player base has migrated to mobile. Many in Hearthstone’s Reddit community have suggested the increase might be due in part to people buying card packs on Android emulators, where they can cost less using Amazon’s virtual currency. But that could hardly account for such a huge revenue increase.