Answer:
Nothing. Advertisements are not a valid source of scientific evidence since they are testimonials.
Explanation:
Testimonials are an important toll in marketing industry and are often used to show the efficacy of a product such as this "Fit-Gadget". It is not unusual to for people to base their decision on this testimonials even though they are not grounded in science. This factor, of not being based in scientific evidence discards them as a source of reliable evidence.
