> If Amazon wanted to start pushing more into local markets (or different kinds of products), they can make a fortune off this data, and that's why they can afford to undercut companies like Square. It's a long term play.

Possibly. Alternatively, Amazon seems to operate under a business model something like: 1) enter an existing market with a product offering that is at best the same as the competition 2) undercut said competition with unsustainable pricing until you drive them all out and have a monopoly 3) raise prices, profit