> I would like to understand why people are so enamored with Costco

The first thing someone told me when I got to the US was to go to Costco, pay the membership and get an AMEX charge card for Costco.

If you are someone with zero credit history and want to buy groceries without having cash on you all the time, then Costco is a big part of the "welcome to America" package.

What Costco lacks in variety, it made up in quality and quantity (no, that's not a choice). The food is good, most things are sold at cost, gas is cheaper, diapers are cheaper ... everything with a Kirkland label is middle-of-the-curve good.

So Costco runs become a regular thing. Before you know it, it is like church - go there, show your membership and eat the wafers.

Not quite a religion, but something you still proselytize.