It's indeed possible but you'd need to look at software that is more in demand. With the odd person subscribing to your game you might be able to pay for your server if you're lucky but to actually live you need much more. Private servers for online games are quite lucrative if you're morally okay with them and have the ability to run them correctly which most owners don't.

If you want inspiration go trawling through small time game company websites. If they have the games people want then they generally take off. Xgen is a good example, look them up when you get the chance.