Thanks for sharing this. Fascinating article.

I don't remember the timeline Out of Print was
implemented. However, it's not too hard to implement
it if you think about it. The OP search provides very
little information and is more title based than ISBN
based. For example, when you use the OP search it
returns both hardcover and paper options for the same
title. No description other than what shape the book
is in and the cost, which is why most customers I do
OP searches for don't follow through and make a
purchase. The main reason it's simple to implement is
that all the info comes from what was probably an
existing database: Alibris.

Long before the Alibris search in Bookmaster, BN.Com
offered used book options online by partnering with
various used bookstores (not just Alibris). However,
I think this came after amazon.com's similar offering
of used books being sold by any Joe/Jane. When I'm
unable to find a used book for a customer in
Bookmaster I always make sure to point the customer to
bn.com where there are more options.