[dundarious]

Costco also tend not to sell bad or mediocre high price items. If you buy a somewhat expensive vacuum cleaner (that is still a good deal relative to other retailers), it's pretty much guaranteed that it's a quality product, less likely to be built poorly, unlikely to break easily, etc. Costco functions as a kind of Wirecutter like review service.

[fmajid]

The term “curation” is overused, but that is definitely an aspect of their success, just like Trader Joe’s.