Funny you should mention that, Max. I get emails from people all the time who are skeptical about SBI!. Which is certainly understandable with all the hype out here. One guy told me he though all those stories on the case studies page were fake.
I told him why not just e-mail the people on that page and ask them?

Their websites are listed right on the page. That's one way to tell if a testimonial is genuine or not. If they are listed as "Tom from Oklahoma" as so many companies do, you know those are usually fake, but SiteSell actually lists the person's website address so you can always contact the people if you have doubts.