Good question. I guess things like a comment/like/reply mechanic. And, RSS feeds don't really have a topological linking mechanic as far as I know. I mean, this

Good question. I guess things like a comment/like/reply mechanic. And, RSS feeds don't really have a topological linking mechanic as far as I know. I mean, this stuff doesn't seem that hard. It's just that users prefer the walled garden approach, which is too bad. Email came around early enough to avoid that. If email were invented today, it would work like Snapchat or Slack or whatnot. Email is a much better system IMO.