Infomercials and the internet are notorious for false advertising and for promoting fraudulent products and services. To demonstrate the superiority of their product, sellers subject viewers to video clips showing the inferiority of a competing product. But the video, produced by the product manufacturer, is shot in such a way as to make the rival product appear worse. Notice whether the product or service is supported entirely by testimonials, or by controlled scientific studies. Testimonials are the most popular tools of deception used by modern day marketers.
Testimonials are when individuals offer anecdotal evidence based on personal experience.
This experience is problematic because it hasn't been tested against control subjects, so the individual doesn't really know if the desired outcome is because of the product or some unknown factor. Testimonials are sometimes even staged. Yes, people are paid to endorse and promote products they've never even tried - it's called acting. Testimonials work because they showcase people who have succeeded at something such as losing weight, developing washboard abs, rubbing away their cellulite or becoming a better lover. Viewers are attracted to successful people, hence to the product that made them successful.