Same experience here. I buy books from them frequently (Prime) and it's been years since they had proper packaging for books. It must save them time and money. I can't help but wonder if they're playing a numbers game, with a spreadsheet model showing it's more profitable to do it that way because "enough" customers will tolerate it and not demand an exchange. If a book arrives damaged I request an exchange, and have never had a problem doing that.

PS: Been reading HN for a while now. This is my first post.