Chris Aldrich's discussion of the rewarding discovery that a friend has read something that you are reading, before you see it in their feed, is spot on. It is fun. And it reminds me of two things. The most important is that I really need to get to grips with my tags, both in Zettelkasten and, perhaps even more importantly, in Pinboard.
The whole business of bookmarking, storing copies, highlighting and annotating remains a source of confusion for me. There are just too many moving parts. I quite like Chris' suggestion of making it a topic at a future IndieWeb Camp. I've got two projects on the go, either of which could be my thing in Nürnberg in a couple of weeks.