An organization called the Authors’ Guild is hassling Amazon.com about the way that used books are sold on the site. Jeff Bezos is trying to drum up support for his efforts to defend the company from the attack, and Tim O’Reilly published an open letter in his weblog defending Amazon.com’s marketing of used books. As someone who earns a handful of change on every new book he sells, and jack on every copy that’s sold used, I support Amazon.com’s marketing of used books on its site. The only reason one might oppose the sale of used books is greed. If someone wants to buy my book used, or borrow it from a friend, or sit and read it one page at a time on the couches at the local bookstore, I fully support them. If earning a bit of cash is more important to an author than the dissemination of knowledge, I suggest that they find another line of work. That said, if you really like an author’s work and can afford it, buy their books new. It’s tough to make a living as an author.