This is the reason why Microsoft and Google have both been investigated for anti-competitive behavior even though neither one of them was a monopoly.
The Sherman Act prohibits using a dominant position in one area as leverage to exclude competitors in the same or different area.
In other words, a dominant player has to play (more than) fair in any new markets.
I say "more than" because if Amazon was not so dominate in ecommerce this behavior would be perfectly fine.
This is the reason why Microsoft and Google have both been investigated for anti-competitive behavior even though neither one of them was a monopoly.
The Sherman Act prohibits using a dominant position in one area as leverage to exclude competitors in the same or different area.
In other words, a dominant player has to play (more than) fair in any new markets.
I say "more than" because if Amazon was not so dominate in ecommerce this behavior would be perfectly fine.