lol, I don't think you know what a failure is. By your definition, every MMO is a failure because one day they will be shut down.
Guaranteed to make money that's why every MMO that copied WoW lasted for years and made tons of ca.... OH WAIT:
Oh sorry, the current strategy is to just go F2P and turn the game into bigger trash.
WoW's design past TBC/WotLK (which ARR Xeroxed off of) is so good, that is why they haven't dropped in subs.... OH WAIT:
(Someone added the last part for WoD, but as of Aug, is at 5.6Mil:
http://ca.ign.com/articles/2015/08/0...-to-56-million)
I love how people point to Post-TBC as some epitome of MMO grateness when WoW's been losing subs left and right.