[nimih]

Yeah, the human being behind the counter will probably ask "why the hell are you ringing up each book on a new credit card," to which the OP would presumably answer "I'm buying books for work and this is how they make me do expense reports," and both would continue to go about their day. Perhaps part of the OP's point is that the efficiency gains of Amazon over B&M retailers (from the POV of the company owners and investors, at least) come at a very real cost to the customer experience.

[rootusrootus]

When I was younger, in my teens and early 20s, carding was a thing. Good old stolen credit cards used in person at retail. This was in the late 80s, before the Internet became A Thing. If you had walked into a store and started swiping multiple cards, they'd most likely have called the cops.

[umanwizard]

Even if they all had the same name?