Amazon is a huge e-commerce site that operates with brutal efficiency. It started out as a book seller but it is now a place you can buy pretty much anything, with zillions of third parties selling merchandise of dubious provenance through them.
As it grew from a book seller to what it is now, Amazon took a huge amount of business away from both the small booksellers that this book discussed in this article is mostly talking about, and the larger chain bookstores that were crushing a lot of those small booksellers underfoot at the time.
Hence, the irony: the first link is to buy a copy of this book about the virtues of small bookstores on Amazon, the company that ate a huge percentage of American retail stores, starting with books.
Fine, you pedant, it’s ironic that a textually sympathetic review of a memoir lionizing the virtues of secondhand brick-and-mortar bookstores, while fretting about their continuing viability as a business model, would link to the book on Amazon, a online-only store commonly considered to be the primary disruptor to that business model. Happy?