In advertising, the use of testimonial is one persuasion technique and also one type of fallacy in which one idea, product or service is advertised by using the positive testimony of people especially of people who are famous or considered as an authority in the field. This is very common nowadays to promote all types of products, despite it is considered by some as unethical because there is no real evidence or reasons presented to advertise the product but just the prestige of someone. This type of technique is the one included in "An advertising campaign in which a popular comedian promotes a brand of soft drink" because, in this, a testimony of someone famous is used to advertise a product rather than evidence or reasons.
