Here's strategy that really works. It was passed on to me, but I think Jay Abrahms is the creator.I'm going to use a real life example. Right now, I'm creating a "how to make money from green energy" product.
So I went to Amazon.com and found two similar products as my own. One with a lot of bad reviews and one with a lot of good reviews.
First the bad. This book is sold here in the US on a TV infomercial as a way to make money from green energy. Read the comments and reviews about it here:
http://www.amazon.com/Green-Millionaire-Nigel-J-Williams/dp/1439222126
A book about making money with "green" tech with good reviews:
http://www.amazon.com/Sunshine-Dollars-Steven-Harris/dp/1603220003/ref=sr_1_1?ie=UTF8&s=books&qid=1289663836&sr=1-1
Just by reading the comments concerning both books I know what to put in my product, what to leave out. And to write the sales letter, I just need to address the major issues and benefits brought up by both sides.
Amazon comments are great for FREE "customer satisfaction" research to help create info products as well as sales letters.
-Boom boom boom boom.