I always enjoy seeing stuff like this. While it may not make a ton of economic sense for a guy working at Google, I'm happy to see people fill niche knowledge s

I always enjoy seeing stuff like this. While it may not make a ton of economic sense for a guy working at Google, I'm happy to see people fill niche knowledge spaces because they can. It's interesting that the paperback copies sold the best -- I would guess it's because these books are given as gifts (and bought by parents). If anyone has data on this behavior for fiction I'd be interested to hear it (I publish an online science fiction magazine, compellingsciencefiction.com).