[setum]

> and then punishing them if they sell somewhere else that has lower fees for a lower price

how would Amazon know if a particular seller is also selling elsewhere?

[jannes]

I have read that they even go so far and crawl+scrape other shop websites.

Of course that is hard to prove because they have plausible deniability.

[DaiPlusPlus]

The trick is to have “Amazon-exclusive” SKUs, or vice-versa: “NotAmazon-exclusive” SKUs that are ever-so-slightly different to justify a different price.

[myself248]

There's a "report lower price" button that shoppers are incentivized to use...

[lallysingh]

A web crawler

[teawrecks]

Eyeballs.