Those who have never read a paper book may be forgiven for asking: what's a page number?
Amazon's Kindle customers aren't among them. The printed page is fighting back; witness today's announcement by Amazon that version 3.1 of their Kindle software will add real page numbers.
"Our customers have told us they want real page numbers that match the page numbers in print books so they can easily reference and cite passages, and read alongside others in a book club or class."
This is, of course, the age-old problem of portability, the very problem that PDF solves so neatly. Users want to be able to reference specific content regardless of medium, and the bottom-line mechanism for referencing content remains the printable page.