The Amazon wishlist functionality is a way for friends and family to find out what things you want/need. Knowing what to get someone without having to ask them is a problem that is encountered quite often, hence this service is a good idea. It ties in two of the aspects outlined by Cialdini: 1) Liking: You probably like the person you are buying for. If they use Amazon, maybe you should too. 2) Commitment/Consistency: The products they have on their Amazon wishlist will be links to the products pages on the Amazon site. Out of consistency you may be likely to buy the exact thing they have linked in their wishlist, i.e. buy from Amazon.