While I've long been a believer in free to play since the days of MapleStory beta in North America (2005), I never expected it to be this successful so quickly. According to a recent report by SuperData, free to play MMOs have 92% of the playerbase and 87% of the revenue of the entire MMO market. Keep in mind though, Superdata's definition of an "MMO" is similar to our own here at MMOs.com (so it includes things like League of Legends and Hearthstone). While a majority of free to play revenues come from Asia, North America and Europe are still growing markets. The size of free to play PC games market is expected to increase from $18.6B today to $21.3B in 2019:

The top few highest revenue generating games on the list shouldn't surprise anyone, as they've been dominating the highest grossing games list for some time now. Keep in mind the data for individual games is only from January-November, so we're holding off on updating our most profitable MMOs list until Superdata releases more complete data. Most recent data suggests that League of Legends brings in a whopping $150M per month. On the MMORPG front, Dungeon Fighter Online continues to out-earn Blizzard's World of Warcraft, taking the #3 spot of highest earning PC games while WoW sits at #4. A list of the top 10 earners across the PC, Console, and Mobile platforms is available below:

Source: SuperDataResearch.com