An idea a day: 15. Develop a ad company giving free plastic/paper cover to bookstores, which can give to book buyers for protecting their new books. For book lovers like me, I always want to keep my tons of books neat and new, one way is to buy plastic cover for the books. It would be very nice if a bookstore can give me covers which exactly fit the book for free. There is no free lunch, book covers aint free, but if the cover have ads on it, the ad fee can certainly cover the overhead.