As PG was opening a couple of packages of hardcopy books for Mrs. PG (she does read a lot of ebooks, but, in some cases, used books are less expensive and some books she wants in hardcopy to share with family and/or friends), it occurred to him that Amazon has almost certainly given used booksellers an opportunity to reach a far wider group of prospective purchasers than were ever available to them in physical used bookstores.
Most of the hardcopy used books that arrive in the mail come well-packaged and most are clearly packed by more sophisticated equipment than a roll of stamps and a stack of envelopes.
So, is PG correct about Amazon and used booksellers?
Has the ability to sell to a much wider online audience affected the pricing of used books?
Has the used book business undergone consolidation with small used bookstores closing and selling their inventory to large, online-focused used booksellers?
Are there people who are paid by larger used booksellers to be scouts for large quantities of available used books?