Influential BLOOMBERG BUSINESS WEEK takes up the media question: What Is a Book?
The answer seems to be that it's an evolving kind of long-form journalism. Yeah, put together some essays or blogs, write and write until it "feels" like a book, and/or create something bookish but only shorter.
As Matthew Ingram notes in the BLOOMBERG BUSINESS WEEK coverage, authors can make plenty of money in this chaos. For example, Amanda Hocking earned $2 million by self-publishing 12 fiction books for the tween and teen markets. Meanwhile, traditional authors, editors, and publishers seem like deer caught in the headlights.