There are e-versions of print books available for download to pocket readers or a computer. I've nothing to say one way or another on those. For the rest:
No one said it better for me than SFWA:
http://www.sfwa.org/beware/epublishers.html
Stephen King's
Riding the Bullet came out as an e-book.
It tanked. Big time. They later brought it out as a print book so they could make some money on it.
If a mega-seller like King can't make squat in e-publishing, what chance do the rest of us have?
Since they started offering them I would dip in and check out the sample reads of various e-books.
Unless it had been previously published as a print book or had been written by an experienced print published writer, I was consistantly disappointed by the quality of writing and editing. I've been told there are lilies growing in the e-swamp, but have yet to find one.
I have bought exactly ONE e-book, ever, and then it was only to research the publisher. That house is a cut above the rest, but their quality still varies from almost decent to bloody dreadful. The book--which was the best I could find in its genre--was mediocre and could have used an edit.
With one e-publisher I offered my resume as an editor because it was quite clear they were wholly clueless about the basics of editing. (It was not PA.) I never heard back from them.
E-publishing is here to stay, and perhaps the quality of product will improve, but as an industry it's been dragging its feet on that point. Since they don't pay an advance, they have no vested interest in putting out a good product to make back their investment. Too many of them state that they will "respect the writer's work."
Soon as I see that phrase or a variation on an e-book site I leave without buying.
The e-book industry has its place, has its readers and supporters, but for a writer wanting professional credit and recognition, wanting to get paid for her work and maybe get a little respect from other writers, it is
not the way to go.