one thing that always bugged me is the fact that paper books never really go on sale or drop in price unless they're a remainder that they can't even give away or it's a huge title that drops a few bucks the week of release. a copy of book x will sit there and rot at full retail price until it's finally removed from the shelves. you have new, you have used, and there's no in between. movies drop in price, music drops, video games drop but books will sit there at $7.99-$15 forever.
if pubs/book stores want to sell hard copies, toss a few price drops, sales or coupons the customers way like every other entertainment media does.