Not only for onboarding, but also for delving while being an experienced Nostrich. I like how texts' highlights in highlighter can be filtered by follows and network (follows of follows) . If I am a physicist (for example) and I'm trying to gain insights into a text, I can follow an authority in the subject and then see the highlights of their follows. Then I can follow some of then and my "network" eventually grows stronger and stronger over that topic to become a supercharged source of information 

 Exactly! Unprecedented high signal in the feedback loop of curated insights + curated community. 

Highlighter is the perfect example of that