Amazon last week announced sales of ebooks on its us site had outnumbered hardbacks for the first time , stunning casual observers , even if it had not been entirely unexpected in the trade .
Whether it 's diamonds and water or hardbacks and e-books , the only cogent explanation for prices comes from the austrians , not the classical economists .
The publishing industry has become the latest victim of the digital era as amazon has announced it is now selling considerably more e-books than hardbacks .