I think it's a perfect opportunity for him to learn entrepreneurship. Instead of discouraging him, perhaps help him understand the economics of it. If he thinks he is running a business, perhaps help him calculate how much he is earning per hour of gaming instead of the absolute value. If the amount of money he is making per hour is low, you could persuade him to reconsider spending so much time on the games as it could be giving very low returns. Alternatively, perhaps help him think of ways in which he can expand his 'business', such as through derivatives like making money from walkthroughs or streams (Robert Kiyosaki). Other lessons could include the cost of running a business, such as making him buy the hardware using his own money and paying for some portion of the electricity bill as part of "overhead costs". Some of these lessons could be very valuable and something not taught in schools. As for other children spending their parents' money, it is something that's out of yours and your son's control. Even if your son does not sell his products, those children will be spending the money elsewhere. Having said that, if your son is spending more and more time on games and neglecting other areas of his life such as studies and social life, then a good talk to grant him some perspective would be useful. Ultimately, I think this is a valuable opportunity for your son to learn some lessons about entrepreneurship, specifically about opportunity costs and return on investment of time.