The sim card in a kindle was a global connect-to-any-network SIM card. Your Kindle was always online and ready to download more books no matter where you were in the world. It was legit actually useful and valuable to customers.

What's Amazon gonna do with a Kindle with an embedded SIM? Spy on the books you read? They already know that shit!

The point is that a similarly cheap always-on SIM in a TV can be used to serve ads if blocking them at the network level becomes common.

I think you're confused. Kindles need to be connected to the Internet so you can purchase and read books on them. The SIM card removed friction from the process e.g. buying books while on vacation or at the airport or whatever.

They didn't put SIM cards in there to spy on you. They were always an opt-in (at additional cost) option for a better user experience.

> They didn't put SIM cards in there to spy on you.

I'm sure Amazon tracked all sorts of activity on those, but that's not the point.

It would be quite trivial to add them to TVs to avoid ad blocking and track behavior when wifi isn't available.