My wife has started using an App (recommended by my sister) which gives her 24 free photo prints per month. All she pays is postage (£2:50 for first order and £3:99 thereafter). She has received her first photobook, thus so far so good. My sister has been using it for some months. However it is a business model that seems to me to be unsustainable. They may make money from extra prints, but I suspect most people will be using the free print option. Something that costs them. I’m very sceptical. Can anyone reassure me that sometime in the future my wife won’t find the credit card account empty?