Fletch you are right, sharing a book with somebody else is depriving the publishers/ authors of money, even the gaming people are trying to stop the buying and selling or sharing of used games.
Check this out
I was wathcing BBC Click and they were talking about the next generation of games consoles will not allow you to use a used game on them. Shops who buy and sell/rent second hand games are taking money away from the people who make the games
How next-generation consoles may eliminate the used gaming market
While internal teams at Sony, Microsoft and Nintendo are all hard at work designing and revising new console hardware, at least one next-generation console manufacturer may implement a way to kill used game sales faster than digital downloads.
Gaming publishers have already been fighting the used game market by locking content within the game until a a one-time use code is entered. This allows publishers like Warner Bros. Interactive Entertainment to lock Catwoman’s single player narrative within Batman: Arkham City or Electronic Arts to require a code to enable the multiplayer portion of Battlefield 3. Any consumer that purchases a used copy of these games from retailers or other sources is at the mercy of the publisher in regards to the amount of additional money spent on digital codes.
the full story here
http://www.digitaltrends.com/gaming/...gaming-market/
Dosent matter how you share content whether its a book a game or a dvd or something else it is still piracy and you are taking money from the publishers ect..