A hidden market
In the mid-1930s, something happened that would change publishing - and reading - forever. Most people agree it started with a German publisher. He decided you could sell paperback books for a small sum and still make money if you sold 17,000 of them. But Nazi Germany was not a good place to publish books.
Before 1935, if you wanted to read a good book, you had to pay a huge amount of money or go to the library. Allen Lane, a British publisher, believed people wanted to read good books but just couldn't pay for them. He was right, and his Penguin series of paperbacks were an instant hit. Within one year, Penguin had sold 3 million paperbacks.
In the United States
It wasn't long before the Americans began to look at the British publishing revolution. One man, Robert Fair de Graff, decided the trick would be to sell books for 25 US cents each.
His innovation was Pocket Books. They were smaller than Penguin's, so they could fit in a pocket or a purse. He also came up with the idea of gluing the pages - in the past, they had been stitched. Ten books were launched in 1939. One of them was Lost Horizon by James Hilton - the story of a place called Shangri-La. It sold millions of copies.