What I would do is make step by step videos of me ranking a GP listing.
This way you can watch right over my shoulder as I do everything.
I would ask for volunteer listings. This way I can help people that are really struggling now, in exchange for testimonials for the sales copy. (Of course I would give away a couple of review copies, as well.)
Is this something you would be interested in?
Would you like something added to this?
What price point would you like to see this at?