The bad news, Bob, is that you are unlikely to make $27 on anything through Amazon unless it costs several hundred dollars! So you are not going to want to count on this in small quantities to be very worthwhile. But compared to what you get for clicks it's pretty good.

The good news is that it is free and not too hard to do (everything is always represented as easy, right). The rate you get is between 4 and 10 percent depending on the product (electronics get 4% and electronic downloads 10% at any volume, for example) and volume. So a $20 book would get you anywhere from 80 cents to $1.70 depending on your sales volume.

I would look at this as a part of advertising income and something like Lisa's example as something you promote as a major feature of your sales effort. You can get the details about Amazon's Associate Program at: http://affiliate-program.amazon.com/gp/associates/join.

James