The fact that co-founder of Zynga and creative director of FarmVille 2 are behind this enterprise is extremely telling. A few thoughts: 1. There is a small-but-non-trivial segment of gamers that are willing to spend huge amounts of money for in-game privileges. 2. There is a similar, somewhat-overlapping segment of gamers willing to spend huge amounts of time on a game, if that huge amount of time is rewarded with th…
There's nothing leading edge about this. Both western and eastern video game companies have been doing this for more than a decade.
An infamous example is EA, who have been sucking the fun out of their games with this for ages. Bonus points to them for slapping these mechanics on paid games which they sell en-masse by exploiting franchises popular with mass-market consumers, then extracting additional money using the sunk cost fallacy.