The Men Who Make the Ads" by Max B. Sackheim, President of Sackheim & Scherman, The Fourth Estate Aug 14, 1926 (leaf 805)
The pattern
This still is filed under House ad as portfolio.
Define
The firm advertises itself by showing the work, not by describing the work.
Mechanism
Proof by exhibit. The portfolio is the claim. Captions stay short. The pieces carry the argument.
Verdict
We sell craft and the buyer can judge from examples.
Why it works
Positions the agency principals as authoritative experts rather than just vendors. By featuring their photos and explaining their scientific, test-driven approach to copy, it builds trust and demystifies the advertising process.
Steal this when
You need to sell high-ticket B2B services by establishing your team's expertise and methodology.