I'm 2 pages late, But FunFact time:as to comparing WoW and ffxi, http://mmogchart.com/
since there aren't enough games that i could find one where only one thing (server population) is varied between two of them. so like it or not the comparison is made.
From what I understand, Blizzard releases Every Single Character as a subscriber. If FFXI released it based on the number of "Content ID's" that would include mules, or if WoW released it based on the number of packages sold, the margin wouldn't be so wide [albeit they would still lead, I'm not denying that.]
XI Wiki

