[charlieok]

I personally don't mind unread counts. That aspect really depends on the way you use it.

I used to have a ton of unread items sitting in the feed reader; now everything is either immediately discarded or immediately shunted into Pocket. (A good phone interface for me might be: swipe left = discard, swipe right = send to view-later service of choice and discard. Fast!)

Of course, that means I now have a ton of unread stuff sitting in Pocket. So I think services in that category could benefit from this kind of scoring too. I can see my Pocket stuff in reverse chronological order. I'd love a really intelligent, adaptive “sort by magic” for that big bucket.

You suggested using HN as a source. That's absolutely along the lines I'm thinking. It's like this: every site can be a source of stories, but every site should also be a potential source of scoring signals for stories -- either its own or elsewhere.