$50 Amazon.com Gift Card to loyal customers who book again but through the app. Book your next hotel on the TripAdvisor mobile app using a valid US billing address (minimum $150 spend before taxes and fees). Be sure to complete your stay, then submit your review by November 30, 2016. Once your review is published and we’ve confirmed your stay, we’ll email you a code worth $50 for use on Amazon.com. Limit of one (1) Amazon.com Gift Card per person during the promotional period.
Only users who have previously booked a hotel on TripAdvisor through “Book on TripAdvisor”. Previous booking(s) must have been made with the same email address used for the booking qualifying for the TripAdvisor app $50 Amazon.com offer. First time bookings do not qualify for the TripAdvisor app $50 Amazon.com offer.
This gift card cannot be earned for hotel stays at any hotels or properties owned, operated, or affiliated with Marriott and its associated brands.
https://www.tripadvisor.com/TripNews-a_ctr.AmazonBookOnTripAdvisorAppBonus