Americans just love to spend, I heard drone makers in China say Americans have money and leisure, they buy anything.
Here is how Costco in China opened: https://www.youtube.com/watch?v=2UfO4gpML4g
Not to say Americans don't love to spend, I think America has exported this culture to the rest of the world which is that every holiday is an opportunity for sale, put debt on credit card and get addicted to the dopamine rush of shopping. I don't think its unique to America anymore.