SuperData Research reports. By 2017, that number is expected to rise to $13 billion.
In 2014, the No. 1 MMO in terms of revenue is League of Legends, which has so far generated $946 million, beating out subscription games such as World of Warcraft, which is No. 4 on the list with $728 million. World of Tanks comes in at No. 5 and represents the largest revenue gap on the graph at $369 million. Dota 2 is No. 9 with $136 million, and Hearthstone: Heroes of Warcraft is No. 10 with $114 million. See the full graph below.