At the heart of this is the indisputable fact:- People save books!!. This led to many millions of tiny isolated and undocumented collections of assorted books.
People who wanted a particular book had one option - a Used Book Seller(UBS).
These UBS's would open a retail spot and gather books from estates or the public or library disposals of un-demanded books etc. As time passed, they would create a viable business. Time passed and most cities had UBS shops.
Then the internet happened, craigslist EBAY, etc., which enabled anyone +dog to list all they had as line items, author, date, condition etc - often with photos. This enabled the collector to select what he wanted at very low prices compared to the UBS stores, as there was a huge overhanging mass of books that people wanted small $$ for - competition soon drove the prices down. True rare books maintained a higher value - but the mass of pulpable junk swamped the market. USB could not easily bulk buy from these Ebayers or Craigslisters because their business model required them to offer lowball offers.
One by one these UBS died off. Killed by rents/taxes etc. A few who owned their own stores had a degree of immunity to these market forces, but their income fell as well, and after a while they could make more $$ by going online from a cheaper warehoused list and they rented their high street shops to a Starbucks or ??, and never looked back. I travelled in Northern Ontario (Canada) and there was a huge rambling UBS in Cobalt Ontario, with zero rent on owned land - even they eventually ceased = http://www.highwaybooks.ca/ they still operate online in some manner. https://en.wikipedia.org/wiki/Highway_Book_Shop
Rings true to me. I have a lovely used bookstore in my area which has a variety of extremely eclectic stuff, and even he lists his whole inventory online now, as well as maintaining the in-person shop:
Sounds like he has the blessing of owning his own store, so he has no rent burden - the real killer as gentification ruins many places via rent increases.
