Developed by Blizzard Entertainment, World of Warcraft (WoW) is set in the fictional world of Azeroth where players choose to fight for the Alliance or Horde factions.
"Worlds of Warcraft became the first game to surpass a million U.S. subscribers, while gaining a global audience over 4.5 million and counting" (Au, 2005)[1].
Since its release in 2004 two further expansions have been released, adding significantly to the existing content that players are able to access.
World of Warcraft: The Burning Crusade (2006): Adds two new character races, one new profession, eleven new zones and increases the level cap from 60 to 70.
World of Warcraft: Wrath of the Lich King (2008): Adds one new character class, one new profession, ten new zones and increases the level cap from 70 to 80.