That's why I inserted "to be able to". It should be optional. I do not expect payments either.

EDIT
Having had a bit more time to think about it, veeall's point was maybe that the possibility of paid apps might attract more professional developers, which in turn would attract more customers. While I am not sure this is the case - I think cause and effect are reversed in this scenario - I do agree that without professional developers who write Sailfish apps for money, the OS will forever remain "for hobbyists only". Your comment suggests that you are happy with it, but is Jolla? How long can they survive by selling to a bunch of hobbyists?

This is where the paid activation codes come in. I already mentioned Sygic who followed the same path on Maemo. Ergo, I do not believe that paid apps are a necessary prerequisite. So what is? Jolla cannot compete with Android on the number of potential customers, but neither could Maemo and yet it managed to attract at least some big guys. So what is it and how can Jolla get there?