Kitchen folk, athletic folk, old folk, young folk, fair folk, fighting folk, learned folk, high folk, low folk, good folk all keep an eye on Bovril.
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
Listing every type of person normalizes the product as a universal necessity. The humorous anecdote on the back warns against imitators in a memorable way.
Steal this when
You want to broaden your product's appeal by showing that literally everyone uses it.