There is a little known feature of prime: you can read a book (from a selection) for free each 30 days. Theses books cost usually about 4€. 12 * 4€ = 48€. This

There is a little known feature of prime: you can read a book (from a selection) for free each 30 days. Theses books cost usually about 4€. 12 * 4€ = 48€. This little offer (which is usually not even advertised as a prime feature) alone almost justifies the cost of a prime membership. Prime is a cost-center for amazon. It's not meant to make money. It is a customer loyality thing.