Can you? yes. But it's going to be very difficult. Let's say you have a really popular open source project with an enterprise version (which pays your bills).

Can you? yes. But it's going to be very difficult. Let's say you have a really popular open source project with an enterprise version (which pays your bills). Anybody can start up a competing app with similar features and either give it out for free or charge, making it more difficult for you to make money and stay in business. The alternative is to have a service-based business. For one or two people, this isn't very scalable.