In my youth, I worked in a small hardware store, in the days where nothing was prepacked etc.
We could spend 30+ mins on a customer wanting to look at 15 different sized screws, then they eventually buy 10 individual screws for about 7 pence.
My boss would later have a polite go at me saying I shouldn’t waste so much time on customers that are only going to be spending a few pence, other customers are waiting to be served, customers with money to spend....
My initial argument was, the guy who got great service when he spent 7 pence, would likely chose us first when he wanted something more expensive. But with very few exceptions, my boss was totally right, the customers that spent 30 mins of my time spending a few pence because they hadn’t a clue what size screw they needed, came back week after week expecting me to open every box for them so they could again spend just a few pence.
Ok no internet, but books galore showed the various screw sizes, they could easily have worked out what size they needed in advance (or at least narrowed it down to two or three choices)