************World of Warcraft’s Subscriber Definition
World of Warcraft® subscribers include individuals who have paid a subscription fee or have an active prepaid card to play World of Warcraft, as well as those who have purchased the game and are within their free month of access. Internet Game Room players who have accessed the game over the last thirty days are also counted as subscribers. The above definition excludes all players under free promotional subscriptions, expired or cancelled subscriptions, and expired prepaid cards. Subscribers in licensees’ territories are defined along the same rules.****************
when blizzard announces subs, that does not mean that's how many people are playing or have even ever played, it has nothing to do with people, they define subs in their own way because it's 100% legal for them to do so
any time you reference subs in warcraft from now on, understand this.
all businesses do this, you spin things to look the best for you, that's how it all works and how it will always work.
www.daeity.com explains this well and has some other interesting stats too