I always enjoy Valdis Krebs' perspectives on networks. The way Valdis sees the world is interesting and this riff is no different. Getting the data on what users hi-lite is in a way like a peek into a deeper level of our behavior than just the books we follow and the friends we keep but gets at a level of data that may reveal why we like that book, or maybe why we like those people.
It is not just the also-bought data that matters (which books bought by same customer), it is what we specifically find interesting and useful in those books that reveals deep similarities between people -- the hi-lites, bookmarks and the notes will be the connectors. Our choices reveal who we are, and who we are like!
When the choices available are shaped by our culture and policy, the reverse of this statement starts to become haunting.
The choices we have available to us, reveals who we are and who we can become. Working to shape fair choices, healthy choices, and uplifting choices is at the core of lots of policy and social advocacy work.