Pros
Hard work, but extremely satisfying. You see tons of novel items every day (pun intended :) and it's amazing immersing yourself in a warehouse of knowledge and dreams. If you're lucky like me, and find a store with wonderfully intelligent and quirky coworkers, it can be a dream job. Employee discount is genuinely amazing.
Cons
This is not an easy job, and the work is never done. But if you can grow comfortable with the perpetual state of being Sisyphus, then it's extremely rewarding to breath life into the shelves and to help someone find a book or item they'll love (or can't find on their own). You'll constantly cycle new things in and yet-unbought things out of the store (into the many streams HPB as an overall company manages, where good condition unpurchased items can still find a loving home). Customers will get upset about things no one can control. Customers will leave wet fast-food cups on the shelves. Customers will destroy your alphabetical organization and push your books in and make your job way more difficult, like predictably bad whether. But if you can take all these things in stride and not let the bad apples affect your day, then you'll thrive here.