This year only 15% of the US publishers at the Digital Book World event think that apps are a good way to make money. Last year it was 37%. Half of the total said apps cost too much to produce.
I think the reason they're wary is that although there have been a few successes, nobody has come up with an app or enhanced ebook (the line between them is blurred) that has caused people to tell their friends, "You have to get this, it's amazing!"
That's not necessarily a bad thing. It means there is still lots of opportunity for experimentation and I'm not convinced that the killer app will be one that necessarily cost a lot of money.
The challenge is to add in a meaningful way to a product that is wonderfully self-contained. All you need is a book (or ebook), a functioning pair of eyes, and a working brain. If you can think of a way to complement that in a way that improves the experience, the other 85% of publishers will join the current 15% in beating a path to your door, bearing large checks.
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