Overall, the tone and style of your letter is really good. YOu have that down really well. Just a couple suggestions. First, the box comes down for me to sign up for your e-zine, and it won't go away. I can't click it away, so it blocks the text I'm trying to read. So I suggest you fix that little bug.
Second, I don't think you're telling enough about what your program is. As someone who does have 20+ pounds to lose, I'd want more info before committing my money, even though you offer a strong guarantee. I suggest you elaborate more to build my trust in your program.
Eileen
Copywriting that gets results!
www.eileencoale.com