"Can't forget the addiction factor" Because people get addicted to games that aren't doing something right, right?
It's large player base came from somewhere, and as previous times have shown losing millions of subs in under a year is possible, funny though that they are gaining them again but apparently they are showing the same trend as release which was gaining 10+ million subs in under 2 years.
Relationships in this game? Yeah that would be a factor to help some hold on for say a couple of months, not 10 years.
Did you really just compare marriage and MMOs? I'm not even going to reply to that comment.
Very few MMOs have even scratched their numbers, WoW's numbers fall because of Blizzard decisions, mistakes, and typical aging.