A testimonial or endorsement is a written or spoken statement, sometimes from a public figure, sometimes from a private citizen, extolling the virtue of some product, which is used in the promotion and advertising of that product. The term "testimonial" is most commonly applied to the sales pitches attributed to ordinary citizens, whereas "endorsement" usually applies to pitches by celebrities.

Written testimonials

Testimonials in the form of letters and ad copy were a common feature of patent medicine advertising in the 19th and 20th century. The pages of almanacs and other promotional literature were filled with pages of testimonials, some with accompanying photographs, that tell of the healing powers of the products in question. Dr. R. V. Pierce, marketer of Pierce's Golden Medical Discovery, published The People's Common Sense Medical Adviser in 1875; it was still being offered to the public forty years later. In addition to a fair explanation of medical knowledge at the time it appeared, this book contained literally hundreds of testimonials extolling Pierce's nostrums, or talking up the virtues of Pierce's Buffalo, New York clinic. Stern photographs of women who owe the cure of their "female weakness" to Pierce's medicines accompany many of the letters. A Denver, Colorado man's testimonial affirms that they put an end to his "self-abuse:"

Case 461,306. Onanism. Melancholia; contemplated suicide.

Gentlemen — Having waited several weeks after finishing the last medicine, to see if there would be any relapse, I now send you a report of treatment. I believe I am thoroughly cured, not only of poor health, but of all desire to abuse myself. I have regained health, spirits, and confidence. Am married, something I have long desired, but never before dared to attempt. Please accept my sincere thanks, gentlemen. Your medicine has saved me from a suicide's grave.

--- H., Denver, Col.

Not only anonymous Coloradans afflicted by sexual fantasy, but occasionally politicians, entertainers, and other celebrities offered their endorsements to the patent medicine makers. Perhaps the most valuable testimonial ever was acquired by the makers of Vin Mariani, a cocaine-laced patent medicine, who were best pleased to receive the recommendation of Pope Leo XIII. Queen Victoria also endorsed a number of patent medicines and other products, and the frequently seen notices that a product is "by appointment to" a monarch or his family continues the practice in a somewhat more low key manner.

This coup, unfortunately, was scored at the end of the era. Later advertisers found that no one bothered to read the testimonials anymore; the sheer bulk of their numbers made them no more convincing or appealing. A warier public wondered whether these anecdotes really proved anything, and their genuineness was often doubted. Celebrity endorsements remain with us. Occasionally the makers of a consumer product do in fact use a consumer's letter in its praise in an advertising campaign. But for the most part, the bulk presentation of written testimonials is an advertising technique that has fallen by the wayside.

Modern testimonials and endorsments

Today testimonials and endorsements are most common in television advertising, particularly infomercials. For example, a smiling upper-middle class mother might explain how excited she is about a laundry soap and describe the benefits that she receives from using it. Marketers feel that the use of testimonials adds a personal touch to their appeal and also portrays a populous image. To be effective the testiment should be from a person with a similar demographic profile as the people in the target market. This is not true for celebrity endorsements: In this case the goal is to use the recognition factor to draw on the halo effect. In theory, this source credibility is transferred from the celebrity to the product, brand, and company. The main problem with using celebrity endorsements is that any negative publicity that the celebrity might get will also be transferred back to the product, thereby reducing brand equity.

An established cartoon character who is hired to endorse a product is called a spokestoon.

See also, damaging quotation