The International Herald Tribune has an article on the relationship between eBooks and print editions that's worth a gander. Snippets:
If e-books remain a dubious proposition for publishers, it may be because they are not compelling to readers. Take "The Da Vinci Code." Amazon sells the hardcover version for $14.97 and the e-book for $10.17, a saving of just $4.80. Perhaps most important, you can easily pass the hardcover along to a neighbor who hasn't read it (if you can find one), but thanks to digital rights management, you can't loan your e-book to anyone.
Some authors have concluded that the best way to make money through e-books is to give them away. Michael Palin, the former member of the Monty Python troupe who is now a famed travel writer, has six of his books online at www.palinstravels.co.uk. James Randi's "Encyclopedia of Claims, Frauds, and Hoaxes of the Occult and Supernatural" just went up at www.randi.org. Baen Books, a successful publisher of science fiction in hardcover and paperback, offers 40 titles for free download.