The two are very different. With a book, you have a reasonably known quantity and it's much easier to ship it back. I'm half convinced people keep IKEA furniture because they can't figure out how to get it back in the box.
You don't necessarily need to disassemble and return it in the box. I bought and returned two bedside tables (HEMNES) recently. I only constructed the first and was unhappy with how it looked once it was in my room. They accepted the returns no questions asked.
Has that changed? I know several who have complained about needing to return it in its original packaging. At least I'm pretty sure it was IKEA that they conplained about - and there have been several.
I'll defer to you, as I haven't actually even been in one, personally.
I don't need to see a book to get an idea of it's contents. I do need to lay on a couch to see if it's something I'd feel like taking a nap on.