No idea. I've asked the same question; I've read all of Gladwell's books (and essays on his site). I've enjoyed almost everything he writes. He's great at telling pop-sci stories. Most can be read in a sitting or two. Sometimes it's nice for your non-fiction to not read like a textbook.

But, apparently the HN crowd only reads Shakespeare, Dostoevsky and Hemingway.

My all-time favorite link to share in a comment on HN is this one, by Peter Norvig, LISP hacker and director of research at Google:

http://norvig.com/experiment-design.html

This link responds to a lot of new stories (and not a few comments) that are posted on Hacker News each day.