If this is true then they must be only location testing new Kindle subscribers. I purchased my first-gen Kindle a few years ago and have been purchasing US book

If this is true then they must be only location testing new Kindle subscribers. I purchased my first-gen Kindle a few years ago and have been purchasing US books without a problem since registering a US address soon afterwards. There is an option under "Manage your kindle" -> Country Settings where you can select your country. Mine is currently set to US and I dont have a US credit card or IP proxy etc.