Gillette razor blades ad featuring Jack Dempsey, Modern Mechanix 1938
The pattern
This still is filed under Celebrity endorsement.
Define
A named, recognizable person lends their reputation to the claim. The name is the proof.
Mechanism
Transferred authority. The reader believes the person first, the product second. Fame or office does the work a peer testimonial does not.
Verdict
The endorser is actually known to the buyer
Why it works
The endorsement is built on relevance rather than fame alone: the ad first establishes why shaving is a professional problem for this particular man, so his choice carries information instead of just celebrity. The quote is written in his own idiom, spar around, no temper for nicks, which keeps it sounding like speech rather than copy. The second bullet flips to the reader with an insult framed as a question, making your face a proving ground for misfit blades, which converts saving money into risking your appearance. The close then removes the price objection the ad just created by restating the cost as less than a cent a day, and the small-caps reminder keeps the stake in view.
Steal this when
Use this when an endorser has a real, explainable reason to care about your product category more than an ordinary buyer does, and the competitive threat is cheap substitutes. The structure - hard case testimonial, then the risk of the cheap alternative, then cost per day - is the right one when your product costs slightly more and the difference is invisible on the shelf.