An article from 2013.. on Micro-Socials... Interestingly enough they categorize Linkedin as micro-social (wrong imo, but i get the idea). The important one they mention is Path.. a Cocoon predecessor. Mastodon fits right into this conversation, but is made exceedingly more interesting by way of the federation. Food 4 Thought

https://socialmediaclub.org/blog/from-the-clubhouse/micro-social-networking-the-future-of-social-media