I don't have many writer friends, but I think most of them post fics and stuff on tumblr and the AO3. They have the same follower model as well. In fact, on the AO3 you can't even see who follows you, only a count of how many.

Medium to me feels like it's mostly oriented for technical bloggers (even though it sucks for technical blogging!) and success bloggers that tell you to wake up at 4 AM and meditate.