There have been numerous public grocery store companies over the decades, so the financials are very well understood at this point. They're all notorious for very poor margins. Most of retail in general is famous for mediocre margins to begin with, and then inside of retail, near the very bottom, is the grocery business.

Take Whole Foods an an example. They're a top tier margin company inside of the grocery business. Their net income margin is typically 3%. That's a good outcome in the business. The net income margin for Sprouts Farmers Markets the last three years: 2.5%, 3.5%, 3.6%.

The retail business in the US also happens to pay among the highest corporate income tax levels on the planet. Whole Foods paid 38.6% last year (almost 39% the year before that); Sprouts paid 37.6%. They get squeezed from almost every direction.