This is just an idea, and probably very stupid, but hypothetically this is how it would go:
You add a lot more businesses (products) so you get much more players. I am sure you would get it as this is really excellent game from many perspectives. Without new businesses (products) there is not much chance to grow imho. With more players and more businesses, stock market would be also be booming so that would be addition to more businesses.
Fun starts if you manage to get a lot more players, and start selling advertising for RL companies instead for ours (if for example 10,000 players would to play, you would not get much chance for advertising in world business anyhow, and even less if 1 million players start to play - its only so much time in a day, 24 advertising spots so it doesnt make sense to be for inworld players).
Then you split the profit from RL advertising with players! Thats the thrill! Play online money game and if you are profitable you get RL money too.
We live in crypto currency era and payouts like that are very much possible without much hassle. It can all be automated especially if you were to take advertising income in crypto too, but even without it you coud do payouts.
This is not a standard feature, but it is quite possible that if you were able to earn RL money from playing a free game that it would be a game booster.
Food for thoughts.
Edit: It would also be a prime example of sharing economy.