WoW could have kept me and others as subscribers, if they had devoted more content that was similar to 1-60. WoW was fun and great 1-60. Had they added more quests similar to those in 1-60, I and many others would still be customers.
However, post 60 they decided that the future players should be stuck in instanced PvP and Raid grinds. Taking a look at Guild Wars, it makes me wonder if the competant devs left WoW for GW.
WoW only has around 2 million players in the USA, many of whom have quit playing. The mass of their player base comes from china. If you don't already know, customers in China have multiple accounts per person because they start losing in-game items** if they play too long, per the Blizzard deal with their government. So this whole 7 million players is quite a bloated number. I know of entire guilds and many other who have quit because we are tired of Blizzard not listening to it's customers.
including over 1 million in Europe and somewhere between 1.5 and 2 million in North America, with most of the remainder in China
**edit: I read about the item loss in an article, but I cannot verify that has been implemented. I did confirm, "Players will be forced to take a five-hour break before they can return to a game." per news.bbc.co.uk/2/hi/technology/4183340.stm