I'm sceptical. What does Amazon know about publishing? With the Kindle, they were already skilled at retailing and designing user interfaces. With their cloud

I'm sceptical. What does Amazon know about publishing? With the Kindle, they were already skilled at retailing and designing user interfaces. With their cloud services, they were selling a service they had to provide for themselves anyway. Why would an author sign to Amazon instead of an established publisher? What could Amazon do better than them?