[Alberta's Child]

Here's the problem with your analysis:

1. Amazon is the dominant retailer in the U.S., accounting for about 43% of the online retail market in 2016.

2. The most recent (March 2017) number I've seen from the U.S. Dept. of Commerce indicate that online sales represent 8.4% of all retail sales in the U.S.

This means that Amazon accounts for just 3.6% of all retail sales in the U.S. This doesn't come close to a "monopoly" by any objective measure.

[DiogenesLamp]

From small acorns do mighty oak trees grow.

At what threshold do you think we should begin paying attention to this? From my perspective, it looks as if they have all the makings for running the table.