As usual, I have to agree with Rob Horning:
Basically publishers have no incentive to encourage people to read books on screens and every incentive to get them to enjoy the fetish of the object. The preference consumers have shown for digitized music and iPods doesn’t seem to translate to books. The usefulness of the iPod derives from its ability to shuffle songs that many people enjoy as background, more or less passively. On the subway I hear about a dozen songs each morning, and it pleases me that they are randomly selected from a list of several thousand. But I wouldn’t want my reading material served up that way. Generally I’m reading one thing at a time, and I benefit from the finality of that decision, when I leave home with one book. Books have the great built-in advantage of preventing me from surfing away elsewhere when the reading becomes arduous or requires an effort of concentration.