It's not 'just a book', it's "enriched". From the AP:
David Baldacci's next thriller, "Deliver Us from Evil," comes out April 20 as a hardcover, an e-book, and in an "enriched" electronic version which will include passages deleted from the final text, research photos, an audio interview and video footage of Baldacci at work.
"I have a pretty cool office, if I do say so myself," the author told The Associated Press during a telephone interview Monday from his office just outside Washington, D.C., where he sets many of his books.
"For a long time it seemed all people were talking about was pricing and the timing of the e-book. And I want to bring it back to the books themselves, to the content, because that's what should matter. I want people to have a great experience and give them a behind-the-scenes look at what I do, the way you would have it on a DVD."
The "enriched" Baldacci release will cost $15.99, according to Maja Thomas, senior vice president for Hachette Book Group's digital and audio publishing. The regular e-book will start at $14.99, then come down to $12.99 once it becomes a top seller, old hat for a Baldacci novel.