http://www.bloomberg.com/news/articles/2016-09-27/more-than-50-of-shoppers-turn-first-to-amazon-in-product-search
I can understand why. Even with the plethora of shill reviews, it's still an easier way to get the general gist of a product looking at the reviews. I always look at the negative reviews from authenticated buyers. You can bet that if someone doesn't like the product that they'll post a review why.
Households Don't Have Warehouse Club Memberships, They Do Have Amazon Prime
https://consumerist.com/2016/09/27/households-dont-have-warehouse-club-memberships-they-do-have-amazon-prime/
We have BOTH Costco membership & Amazon Prime.
I'm seriously considering buying a commercial cardboard compactor :-)
I'm part of the 55 percent. ;D
The combination of Amazon Prime and a nearby Aldi store is a fairly good substitute for Costco if you are single person and have trouble using up the mass quantities of product bought at a warehouse club.
Amazon's Newest Ambition: Competing Directly With UPS and FedEx
http://www.wsj.com/articles/amazons-newest-ambitioncompeting-directly-with-ups-and-fedex-1474994758