Originally Posted by wyndslash
oh, I didn't know that they benefited from even the free books. Strange.
You don't, if the person buys nothing else (common for some people, esp. those outside the US).
Amazon does set a cookie (if you don't have them turned off) to track your affiliate session. It lasts 24 hours OR until you place an order OR you leave the site (close your browser) OR you click another affiliate tag.