My wife and I stopped by the NY LaGaurdia Amex Centurion Lounge for Sunday brunch (yes, we have a flight).
At check-in the chipper receptionist offered cards for a complimentary 6-month membership in Amazon Kindle Unlimited. This must be new as I was here this past Thursday and was not offered a card.
Each card has a unique claim code that must be redeemed by August 31, 2016.
This will opt you in to auto-renewal after 6 months at $9.99 month, so disable auto-renewal if you do not want to later be charged. This is separate from Amazon Prime membership.
Readers, let us know if other Centurion Lounges are handing these out.