Amazon has launched a new book subscription service called Prime Book Box. For $22.99 per delivered box, Prime members can receive a pack of curated books for kids up to 12 years old. Amazon says the subscription saves customers up to 35% off the list price of the included books. Selecting the baby to 2-year-old age range nets you 4 board books per delivery, while selecting one of the other 3 age groups for older kids will include 2 hardcover books per delivery. Customers can “tailor the books from a list of curated options” or be surprised by the delivered books. The program is currently available by invite only, so interested Prime members can request an invitation.