Their willingness to pay should be your first clue

from here

Amazon is willing to pay for our palm prints? Yeah, that's a nope for me, dawg. I'm not interested in giving them a hand at building another biometric surveillance system. Biometrics are forever, you can't get new palm prints, and once you give that info out you can't put the genie back in the bottle.

In theory, Amazon won't track you for the rest of your life because they'll delete the data if you ask them to. And if you believe that, I've got a bridge to sell you. Internet giants don't get to be as big as they are by throwing away valuable data, and data they're actually willing to pay you for? You better believe it's valuable.