I am totally not surprised.
There are a number of games with virtual economies, and have described some of this in TEST's forums. People can pooh pooh the idea if they want, but this is a real way to make money, for at least the last 15 years.
I have a few friends who have had incomes well into 6 figures $USD income by "playing" certain games. Income only works in a virtual economy where you can legally remove in-game currency. This is their full time income. The objective is to broker virtual land rentals, or become a content provider of some sort, or to provide some kind of entertainment or service that people are willing to pay for. That last one is a bit of an open slate, and is a little problematic. Things can degrade very quickly without some kind of governance.
These economies can be very big, approaching in some cases the size of a mid-sized real world city, and make real world millionaires in the process.