To put it quite bluntly all: Those who buy the game, so that only acquires the right that a person (if you assume that each player have their own account "want") can play the game. In a 4-person household (parents, 2 children) would - if everyone wants to play the game with their own account - thus covers any person to purchase the game. A great business model that Ubisoft has thought since. This is but hopefully very quickly backfire because I bought the DEFINITELY LAST TIME of this company a game. Because oh something so great Anno variants may be published in future.
And anyway, why do I actually need an account to a gaming community that do not give a damn interesting to be able to play a purchased for expensive money game offline (offline !!!)? Etc. I have absolutely no interest in any online features
I hope very much that this model of Ubisoft really big goes in the pants. If I were now in the States, I would smooth attempt a large-scale trial against Ubisoft for non-functioning software (and is nothing but this, in my view - BTW: I am the way computer scientists and know what I am talking about) to make an effort.
Supplement: Alas, alas, I have bought the game not on Amazon, but in an electronics market. I would have many 1-star reviews here on Amazon seen and read (which I have now done only), then I would have saved for Anno 2070 me the money.