In this analogy, it would be more like you creating an eBay store called "Strand Books", listing the entire Strand Books' catalog, and then when someone purchases a book from you, popping into The Strand to get the book and shipping it to them.
Except sometimes they're out of the book, and so the customer never receives it. Or you damage the book between the book store and the post office, and they receive a badly damaged book.
The customer is going to be mad at the Strand, not at you. You'd be damaging their reputation.