FWIW, I'm no longer impressed by testimonials in general, but especially in such a subjective experience as massage.
When I wanted to buy a PiscesPro Dolphin II massage chair, one of the things that "sold" me was a testimonial that this chair is used in the Denver airport. I figured if it was sturdy enough for that kind of use, it would suit my needs well.
Post purchase, having a 2-hr layover the Denver airport, I sought out the massage venue. There is not a PiscesPro chair to be found! yet, the testimonial is still on the front page at their website, in present-tense vernacular.
A client once said of my massage, "...that was almost a spiritual experience" which deeply touched me, but to a person that just wants his rotator cuff mobile again, that probably isn't going to be a motivator to call me. Many say that the warmth of my hands is "amazing" and want to know what I used to get them so hot (it's simple friction, and it only happens like that during massage), but there have been couple of times when I've had to apologize for cold hands. If those people had read a testimonial about my hands being like "little heating pads", it might lead them to believe that the advertising was false or misleading.
With this CYA society that we live in, in order for a testimonial to be "readily verifiable" you would probably have to list their name and city in the ad, plus have an affidavit on file with the quote and permission to use it, as well as contact information. Since most people don't want to go through all of that hassle, it was easier for the powers-that-be to simply say: no testimonials.