It was hard for buyers to find on used book marketplaces because sellers would scan a $15 book, their system would pull metadata for a $300 book because of the

It was hard for buyers to find on used book marketplaces because sellers would scan a $15 book, their system would pull metadata for a $300 book because of the ISBN collision, and then you don't know which items are actually for sale until you order them and they arrive in the mail. It's worse when dropshippers get into the picture and there's effectively multiple listings per item. On the other hand, eBay listings for books are usually made for a specific item, complete with pictures of the actual item. It was obvious that the listing was for the real thing.