So the last things I bought through Amazon:
- Advances in Automatic Text Summarization, edited by Inderjeet Mani and Mark T. Maybury
- OpenGL Insights, edited by Patrick Cozzi and Chrishophe Riccio
- Three Rival Versions of Moral Enquiry: Encyclopedia, Genealogy, and Tradition: Being Gifford Lectures Delivered in the University of Edinburgh in 1988, by Alisdaire McIntyre
- Calendrical Calculations, by Nachum Dershowitz and Edward M. Reingold
All were eligible for Prime. None of them are particularly obscure books, but they're not 50 Shades of Grey either. Only one is available on walmart.com. At one point I was a pretty typical Amazon customer. I'm willing to believe the typical Amazon customer has changed, but I still don't buy that they're interchangable services.
Amazon's margins on books have always been essentially zero. Bezos was never interested in being an online bookstore; however, because 90% of all books at the time were sold by one distributor it was easy to set up a website and sell for basically Ingram's price (which was about 40% of retail). Because their warehouses are pretty much bigger than Ingram's at this point, there's no harm in warehousing textbooks. Doesn't mean they're a profit center. And c'mon. We didn't really have to have a discussion about how Walmart doesn't stock Advances in Automatic Text Summarization did we? ;-)
But that's why it's relavent. You can buy a TV from either of them, sure. You can get in your car and go buy a TV without paying shipping too. Personally, if I wanted one I'd buy it from the old phreak up the road's shop, and get stories about sticking it to Ma Bell back in the day along with it. But Amazon has Advances in Automatic Text Summarization, and also uranium ore, and there's a decent chance they have anything else you might want too. That is not a small advantage.
So the discussion at hand is how often a consumer's purchases are influenced by the fact that Amazon has uranium ore and obscure books. I would argue that the availability of uranium ore and obscure books matters only when a person wishes to purchase uranium ore and obscure books; the rest of the time they're buying on price and convenience. Your point about the phone phreak is well taken - consumers, given a choice, will reward people they feel kindly towards. Neither player in this instance has made much headway on that front lately.
I can't tell you how many times I thought, "I'll go to store X and see if they have item a. But maybe they don't, I should probably go to store Y because they also have b, c, d, and e. I don't mind paying a bit extra for availability." Granted, I don't do it as much with online shopping, because I know how to online shop. My mom, however. If she doesn't find it in a store she goes to amazon because she knows Amazon has everything. Needs a gardening tool they don't have at the hardware store? Skip the hardware store's website, go straight to Amazon. I'd argue having uranium ore and obscure books does matter to the customer.I would argue that the availability of uranium ore and obscure books matters only when a person wishes to purchase uranium ore and obscure books; the rest of the time they're buying on price and convenience.