BCharlie

I mention that the data that appears to be used for those purposes is sent again in a separate request to a separate end point, so we have two types of requests: last read location, and reading analytics. Sorry it wasn't clear, I'll try to improve the wording.

That's a great idea! It looks like the 'bad' stuff goes to unagi-na.amazon.com

Though I haven't analyzed other devices (because I don't own them), they could easily have similar issues. I personally really want an open e-ink device, but I haven't seen one for sale unfortunately. For now, I do Calibre ODPS server with Marvin app on a phone, but it doesn't really compare.

Yikes! Maybe that's the next thing I will take a look at...

That makes a lot of sense. I assumed it was somehow for anti-fraud, though I still don't like it.