Maybe it associates the Serial Number (or a UUID) of the device with your accoun...

		spleeyah on Sept 29, 2011 \| parent \| context \| favorite \| on: Kindle Fire - Full Color Kindle with 7" Multi-Touc... Maybe it associates the Serial Number (or a UUID) of the device with your account when you buy it, and then when it first boots, it asks Amazon for the account attached to the device's UUID.