It's submarine marketing for https://www.numerator.com/. It seems like a pretty bad attempt, but I understand very little about PR so it might be brilliant for all I know.

See http://www.paulgraham.com/submarine.html

It's baloney, but they must mean something more than that.

"Roughly one-third of US shoppers are Costco customers," says the article, and Asian Americans are 5.7% of the US population.

I'm not sure how you'd get that 5.7% to be the "average" of any one-third of American shoppers, unless you're tying it to something else.