I wish I had all the answers to that one. That's really the crux of the issue, exactly the way you've put it. I read something somewhere to the effect that the publishing industry really hasn't changed much in 500 years. It's just starting now to have to take this seriously.
You're quite right; it's the selling of the content in book form as we would understand it. That's where the money is made, and it's shared out from that. Of course, we're somewhat like the record industry, I suppose, thinking we can do the same thing with electronic books. Again, the jury is out on that, because a book, like anything else, is still subject to file sharing. There's always somebody who can break a lock. It's fun. It's not for me--I'm hopeless at it--but I think these people just find it's fun to do that kind of thing, and they'll find a way around it; it doesn't matter what you do.
Again, that's what I was saying a bit earlier. We're doing an experiment anyway, providing books free in a certain electronic format, which is basically PDF. We're also using a fancier electronic format, EPUB, which you can actually do something with; we're selling that one, and selling the print book. We want to see if having the PDF available for free will have any effect on the sale of the other books, but we don't know yet. We've just started the experiment and we're going to run it for a year or so.