Boron Letters

Gary Halbert wrote The Boron Letters from prison in 1984, and they're still the gold standard for direct response copywriting. This skill teaches you his core principles: the A-pile test for getting mail opened, finding starving crowds instead of perfecting copy, the 40/40/20 rule that says your audience matters more than your words, and AIDA structure for sales letters. Use it when writing anything meant to generate a direct response: sales emails, landing pages, ads. The methodology is old school but the psychology is timeless. If your copy isn't converting, start here before you tweak another headline.

skills.sh installs: 247
GitHub stars: 150
last updated: Aug 21, 2026

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$ npx -y skills add guia-matthieu/clawfu-skills --skill boron-letters --agent claude-code

Installs into .claude/skills of the current project.

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Boron Letters Copywriting

Master Gary Halbert's direct response copywriting principles from "The Boron Letters" (1984). The timeless fundamentals that separate pros from amateurs.

When to Use This Skill

Writing direct response copy (sales letters, emails, ads)
Creating headlines that demand attention
Building mailing lists and segmentation
Improving copy through the A-pile test
Learning copywriting fundamentals from scratch
Diagnosing why copy isn't converting

Methodology Foundation

Source: Gary Halbert - "The Boron Letters" (1984)

Core Principle: "Become a student of markets, not products." The list matters more than the copy. The A-pile beats the B-pile. Long copy outsells short. And the fundamentals of human psychology never change.

Why This Matters: These letters were written in the 1980s but remain the gold standard for direct response copywriting. Halbert's "coat of arms" letter mailed over 600 million times. The principles work because they're based on human psychology, not trends.