In terms of business, this is freemium. People try out the free (GPL) version, and like it, want premium features, want support, want you to add features etc.

In terms of business, this is freemium. People try out the free (GPL) version, and like it, want premium features, want support, want you to add features etc. There's a subtle competitive benefit of free: by providing something valuable for free that meets people's needs, there's less demand for an open-source free competitor. In a way, this is a nice reward for helping people; but if it's too effective, it can stifle innovation (by avoiding the pressure on you from competitors to improve). Now of course, GPL has other benefits apart from free-as-in-beer: you have the code. You can audit it; add your own features; fix bugs. And if the developer gets hit by a bus, you can carry on without any escrow nonsense, incompleteness, unmaintainable code. It's also a business benefit to the developer, as they can get bug-fixes and features and improvements from the community. But because it's only part of the code that is GPL, they only get part of this benefit. However, typically, the biggest benefit of GPL is bug-reports --- but you still get them from free users who don't have the code. (They won't be as good, but usually the hard thing about a bug is that it exists). You typically won't get much code you can actually use especially if you want to retain sole copyright (though it can be useful to have as a first draft; and have some good ideas). Plus... some people might be reluctant to contribute their effort to someone who's making money (even though they got the code for free). tl;dr: unsurprisingly, free-as-in-beer is far more significant for a business, than free-as-in-freedom.