I don't think it'd work out as planned due to how drastically laws and regulations can differ between various countries. Note how each time some sort of promotion is held for a mount in FFXIV only players residing within certain regions are permitted to participate.

What happens if the law changes in a specific country? How will the business keep track of all the transactions being made and the integrity of legal agreements? What measures will be in place to protect the consumer and service provider against hacking and scamming?

A significant amount of money would be spent on legal fees and cyber security which would inevitably eat into the amount of resources available to make a game into an actual game.