World of Warcraft is the most popular MMORPG in the world, holding records for the number of players and revenue. It is the fourth full game in the Warcraft series (the first three being real-time strategies), and the game takes place in the same Warcraft world of Azeroth approximately four years after the events of Warcraft 3: The Frozen Throne.
The first expansion for World of Warcraft, The Burning Crusade, was released on January 16, 2007; the second, Wrath of the Lich King, on November 13, 2008; the third, Cataclysm, on December 7, 2010. In October 2010, at the BlizzCon conference, it was announced that the fourth expansion would also be released.
World of Warcraft set a world record, recorded in the Guinness World Records, for the number of players — 12,000,000 (twelve million people). With an average price of $25-30 per month, it's not difficult to estimate the revenue for the publishing company.
Speaking of the percentage of World of Warcraft relative to everything else, let's note another figure. The ratio is 62/38, World of Warcraft/Everything else.