But, there was something I didn't consider. The reason that self published authors make most of their money through ebooks is because the paperbacks are too expensive. The printing costs are high meaning the cover price has to be high in order to make any profit. Even just a 50p profit margin is enough to price yourself out of the market, so for many KDP authors, paperbacks are simply not worth the effort. However, children's books are shorter. Less pages = lower printing costs. This makes a huge difference.