Costco performs a credit check when you sign up for a membership. It requires a state ID to sign up for a membership. Like voter ID requirements, this has impacts on the people who shop there. Previously, they also tied the membership to qualifying for their partnered credit card. It is true that you can pay with cash. Ultimately, I'm trying to explain why Costco shoppers look the way they do. It may affect the bottom line to put up these obstacles, because people who meet these criteria can and do spend more.

Walmart only relies ownership of a car to target a richer shopper. Whole Foods and Trader Joe’s, often used for single people or non car owners, locates its stores nonetheless in certain wealthier urban locations. Loyalty cards do not achieve these ends.

The knock on effects are immense. Grocery stores, for normal people, are as much about the discounts as seeing your own kind there. That’s not just economic stratification, it’s also the ethnic groceries, some of them really big, expensive item enterprises (like H Mart).

These are experiences Amazon cannot provide. You don’t get to see the other Amazon shoppers, and you don’t get a sense of whether Amazon is a “cheap” or “expensive” store. And yet this is precisely an experience people want, just as psychologically important as 1 day shipping. Costco, like Amazon, occupies a valuable psychological niche. The question is if there exist any viable retail that does not.