Apple, Google, maybe others charge 15% on up to $1 million or the first $1 million in digital sales. Or less when negotiated. Does Amazon offer reduced rates to small businesses or low volume sellers?

"If anything that's impressive."

I'm conflicted about this statement. On one hand, it's almost passive revenue for the seller. On the other hand, Amazon offloads the risk of carrying inventory and takes half the revenue.

I'd argue that it's impressive with one caveat: the "partnership" heavily favors the house.

Important to note that plenty of other companies will carry the inventory and ship goods out for you (Amazon did not invent the concept of third party logistics) - however if you go to a third party warehouse it is difficult to get certified as 'Prime'.

(Seller Fulfilled Prime is a thing, but in reality is currently closed for sign-up and is really only for the large sellers)

Digital goods have very low marginal unit costs compared to physical goods.

Edit: I was wrong :)

You are misunderstanding the concept of marginal unit costs if you disagree on that basis.

AAA software is wildly expensive, but each incremental copy sold is not wildly expensive.

With a tea kettle, each incremental copy still costs you metal, heating elements and plugs, so the unit margins are smaller.

Oh! That I failed to recall. You are absolutely correct.

It tells me that the fee on digital goods is insanely high.