I feel like if the story is being read by non members than I think Medium focuses more towards showing it to non member only. It may help you get more views but you don't make more money (of course you do) but to a degree. This guy has written a story about it: https://benulansey.medium.com/why-i-include-friend-links-at-the-top-of-my-articles-2cb0c3ca5f25