If I wanted to buy an ebook on how to get a good ranking on Google.com, I'd have to be convinced that you'd actually achieved what you were writing about.
I'd go to google.com and do searches on keywords relating to google rankings and see if your site comes up on the first page of listings. That'd be the best 'testimonial', IMO.
By the way, I went to google.com and searched on these keywords:
search engine optimization
google ranking
google rankings
google top 10
Paul Short
google secrets
google secrets revealed
And your site didn't come up, but I'm assuming that's because you're not finished yet.
So somewhere in your sales letter you should say something to the effect of, "Want to see I know what I'm talking about? Go to google.com and do a search on "a related keyword of your choice" and you'll see that my site ranks #whatever. "
When your site showed up on the first page of listings, only then would I be convinced and ready to buy.
Best,
Shelley
Scam Slam!