Shelf Awareness, which broke the news about Amazon Books, continues to raise questions about the brick-and-mortar outpost of Amazon.com:

Is Amazon Books getting its stock from Amazon.com, which gets extra terms unavailable to most bricks-and-mortar retailers? Are books being bought non-returnable by Amazon.com but being returned by Amazon Books to Amazon.com? How, if at all, is a distinction made between the two businesses--and how will that be handled at meetings in which the bookstore buyers participate?

This is an important distinction to make: publishers sell books to physical retailers under very different terms — discounts, returnability, etc. — than they do with online booksellers. Publishers would likely be very upset if they learned that Amazon Books is selling books that were sold to Amazon.com.