Activity means that you do something useful for the Movement: to spread the word, answer questions in this thread or elsewhere, to create or join a sphere, to do proposals, share ideas, resuming what you think it could be useful and what you love. Not spam and not useless contents: if you don't have anything to say, just don't say it!  You can be active where you want but if your activity is external to this forum, maybe it's better to let it know the dev.