All amazon would have to do is give you credits when you buy both the e-book and the paper book together. That way you don't have to change the price of the book or negotiate anything with the publishers. Really easy. That could be credits toward future purchase or cash back on an amazon credit card, or whatever.
Then Amazon would have to eat the loss. Unlike some electronic entertainment devices, Amazon actually makes their profit on the Kindle sale itself. Unless that changed recently.
Not sure if it changed, but at one point they were literally paying the publisher more for the ebook than the the sale price (link
). Amazon would sell an ebook for $9.99 after paying the publisher $12 for it. So imagine if they included that ebook with the hard copy at a discounted price, and their profit on hard copies is already small as it is. Amazon would be taking it prison-style.
Amazon, as big as they are, was actually barely holding their head above water for many years due to small profit margins. The Kindle changed that (as did the expansion into different retail goods).
It's gonna be up to the publishers, and right now it doesn't look promising. Link: Amazon Goes to Battle with Publishers over Ebook Prices
. Publishing is an old, conservative industry. They may change their tune, but it may be a while.