Can't return if read!

I purchased book at a major bookstore chain, and while hanging out in the 'wireless hot spot' waiting for my trusty laptop to boot, I read the refund policy on the back of the receipt. It states, "Books that have been read can not be returned." I grinned and put the receipt back in the book and wondered:

When is a book read? After you read the last page? Or, is it as soon as you begin reading it? What about if you read a chapter, say chapter three only?

Oh, and don't forget that you have 14 days to return the un-read book! If you try to return the book are they going to ask you, "Sir, did you read the book?"

"Uh, does looking at the pictures constitute 'reading' the book?" "I'm sorry sir, we can't accept this book back!"