Wow.

There's less than five games that can claim to be more successful than Minecraft. And wow is one of them.

7 years but even if you compare launch aligned it's still not close. The WoW subscription model, expansions and DLCs is what makes the comparison unfair.

The one thing Minecraft might have over WoW is merchandise sales.

Minecraft is on mobile. WoW doesn't stand a chance in the long run.

So, currently, you agree WoW is more successful :)

Define success and we can discuss.

I would say Minecraft in all categories except revenue. Minecraft has been able to be a common household name and attract literally everyone, from smartphone gamers to hardcore console or PC gamers, young and old. It is also a fantastic game in that it gives the gamer a blank canvas in which you can, pretty freely, let your imagination run rampant. Minecraft is the Mario of our time and that is a hard feat to pull off. WoW is my personal favorite of the two but there is no doubt as to what game has made the biggest impact.

Pretty sure WoW made alot more money.

A bit confused on what beats WoW success, I can think of franchises, but not a single game. League comes close, but I do not know if it can beat 10 million people paying monthly fees. 

Which is better Adventure Island or Qbert?

Depends entirely on what we're considering 'success'.  If it's profitability, Minecraft isn't even in the top 10.  Warcraft (as of 2015's estimates) is 4th.

http://www.businessinsider.com/the-11-top-grossing-video-games-of-all-time-2015-8