If you spend any time reading their retail forums [1], you'll see almost everyone lambasting Amazon constantly. Either disgruntled sellers who broke the rules and got terminated, or normal, hardworking mom-and-pop stores that were all but forced to sell on Amazon and consistently lose money due to amazon's ever-changing policies, poor support, and catering to large retailers. Large retailers get a direct line and quality support, while most sellers on Amazon get treated like crap.

[1]: https://sellercentral.amazon.com/forums/

The GP claim was

> where so much of revenue comes from the relatively few customers who are very deep in their usage.

I'm disputing that for retail.

If you view the sellers rather than the buyers as customers, then you’ll see that it is the case.

Or maybe it’s just a tiny fraction of those millions of sellers on their platform?

Who would bother writing on these forums unless they have an axe to grind?