Write reviews of books you like. Then add Amazon adds showing just 1 add, which you make exactly the book you are reviewing by specifying keywords in the Amazon box.
Also, consider the Golden Rule of the Bible: "Do unto others as you would have them do unto you."
Recently, I wanted to purchase a GMAT book. I came to hubpages, searched for GMAT review, and then bought the GMAC guide by clicking through that hubber's amazon ad. I also bought another book in the same visit (to qualify for free shipping.)