To add another perspective,thing of how easy it is to get rid of an ebook after your done with it. (done with it by whatever definition you personally choose.) With a pbook you might sell it but most probably don't. If it is good enough to give to someone you know, it's probably good enough to keep - thus taking up space in your home.
You might trash it, helping to fill the land fill and further polute the environment. It could sit on your sheves for years and when you next open it, you could find that termites had eaten most of it. Etc., etc., etc.
With an ebook you just delete it & it's gone. No mess, no fuss. So look at the bright side of ebooks.
