Small companies are never going to make you a billion dollars, but they can provide a decent living. It's like playing decent poker at a low stakes table. Really, it's about making good consistent bets and not taking too many unnecessary chances.
Big guys though, there is no middle ground. You are all in much of the time. A single mistake (like Microsoft and dismissing mobile early on), and you are playing from a big deficit. Running or owning own of those companies would be insanely stressful, and is only for very specific personalities.
This is interesting stuff; for all the content that gets post on styleforum, there's rarely any discussion about styleforum as a platform. You should write some of this up at some point, about your experiences running the forum, the backend legwork etc etc.