- The Burning Crusade - 2.4M First Day, 3.5M First Month.
- Wrath of the Lich King - 2.8M First Day, 4M First Month.
- Cataclysm - 3.3M First Day, 4.7M First Month.
- Mists of Pandaria - 2.7M First Week.
- Warlords of Draenor - 3.3M First Day.
- Legion - 3.3M First Day.
[...] launch-week player concurrency climbed to its highest point since the 2010 launch of the Cataclysm expansion.
Recordad que durante Cataclysm el número de jugadores rondó los 12 millones, por lo que Legion tendrá más o menos los mismos.
Fuente: MMO Champion.