Amazon has begun sending out invites to select customers to try out the Kindle Fire HDX and other devices free of charge for 30 days. According to the invite, customers can choose among any of the Kindles Amazon current offers, including the latest Kindle Paperwhite and new Kindle Fire HDX and HDX 8.9. Amazon will ship the chosen tablet or e-reader to the customer free of charge, at which point the customer will have 30 days to decide to keep it or not. If it is not sent back, Amazon will charge the customer’s credit card on file. Amazon has always offered a generous 30-day return policy on Kindles, but that consists of an initial credit card charge and a refund when the tablet is returned to Amazon. This program requires no upfront cost to the customer — if they don’t like it, they can just return it, no questions asked.