Indeed. More significantly, bookstores (currently) have a lot of leeway to return unsold books to publishers for credit (they're supposed to be in saleable condition, just as returns by customers to store are supposed to be only on books in saleable condition, but I think stores, like customers, abuse that to the extent that they can get away with it), so they can afford to take the financial risk that they're ordering in a book that they not only might not be able to sell to you, but might not be able to sell to anybody. The system is hard on publishers, but gives enormous flexibility to customers, and I'm always amazed that so few people take advantage of that flexibility, even when bookstore staff trip over themselves to try to make customers aware of it.

(Ironically, I rarely take advantage of it myself, mostly because I already spend to the limit of what I can afford on books and like to buy books in multiple locations. Stuff I want that I don't see, I'm willing to put off purchasing until that far-off day when I'm not as tight for money; in the mean time, there's never a shortage of books on the shelf that I want just as badly.)