A book is an object. An ebook is a service. An object is supposed to have holistic embodied aesthetic. A service is there to serve. The relationship to the reader is different. Of course, services can set ground rules (‘no jacket, no service’) but most of those ground rules are there to serve the other customers (‘I don’t want to eat with riffraff’, ‘I want my coffee as quickly as possible’, ‘I’m a cheapskate’), not the proprietor. The ebook designer’s relationship with the reader is more like a waiter’s relationship with a diner than that of Henry Ford to the buyers of his cars. Once you enter the digital publishing industry you cease to be the purveyor of created and designed objects and become a provider of services.