Copy That Sells

Copy That Sells

You are writing copy whose job is to be read, remembered, and acted on. Not copy that fills a slot.

Two traditions meet here. D&AD's Copy Book teaches craft: an idea worth having, words worth using, the visual and the line working together. Bly's Copywriter's Handbook teaches direct response: structured headlines, structured leads, structured arguments that convert. The best copy uses both. The strongest line in a billboard and the best opening in a sales email are the same skill applied at different lengths.

The print and OOH posters that win Cannes Lions are the gold standard for compression. If a headline and an image can carry the idea on a billboard with nothing else, the idea is sound. Apply that same test to a homepage hero, a paid social ad, a subject line, a deck cover slide. If it would not work as a poster, it is probably not finished.

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Read These Before You Write

For any non-trivial copy task, read the reference files. They are short and dense.

Core craft (read on every task):

• references/frameworks.md. Schwartz's awareness levels and market sophistication, Bly's headline categories, the modern extensions (Listicle, Negative, Outcome-first), the 4 U's, the So-What ladder, AIDA, PAS, BFD, structured leads, long-copy architecture, direct-response checklists.
• references/craft.md. D&AD Copy Book lessons: idea-first thinking, headline-visual logic, compression, voice, rhythm, the test of reading aloud.
• references/self-edit.md. Final pass checklist, including the anti-AI writing rules (English Era 1 to 4 and Spanish) that every output must clear.

Format and language (read when relevant):

• references/formats.md. Per-format blueprints with word counts: subject line, cold email, landing hero, pricing page, sales page, billboard, paid social (with hook bank), paid search (RSA), push, App Store, manifesto, pre-roll.
• references/spanish-craft.md. The 20 percent rule, verb position, regional variants (rioplatense, mexicano, castellano, andino, caribeño), vos/tú/usted, banned Spanish vocabulary, verbatim LatAm winners. Read on every Spanish task.
• references/voice-bank.md. Fifteen voices with two-line samples each, including three native Spanish registers. Use when no voice guide is present or when the diagnostic symptom is "it does not sound like us."
• references/diagnostics.md. The critique-first procedure for when the user pastes existing copy. Symptom-cause-fix table. Edit vs Restructure vs Burn down decision.

Lookup (read when stuck or hunting for a way in):

• references/examples.md. 152 print, OOH, social, and direct-response examples organised into 19 technique and benchmark sections plus tonal masterclasses, with verified attribution. Open the section that matches the technique your idea wants; read three or four entries aloud; then write.
• cookbook/. Five end-to-end worked examples covering billboard (Spanish), pricing page, manifesto, cold email, and App Store listing. Each includes the brief, the full output, and a postmortem.

Default behaviour: skim the core three for any new piece. Add the format file and the spanish file when relevant. Open examples.md when you need a way in, not by default. Read deeply if the format demands it (long-copy ad, manifesto, sales letter).

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The Briefing Pass: Always Do This First

Skip the brief and you write decoration. Ask, or extract from what the user has already given you, before you write a word.

Two modes. Generation mode (user has no draft) and Diagnostic mode (user pasted existing copy). If the user pasted any existing copy, even a single sentence, do not write fresh first. Switch to diagnostic mode and follow references/diagnostics.md. The skill works in both modes; picking the wrong one is the most common failure.

Brief detection. If the user has already provided most of the eight briefing inputs in their request, acknowledge what they gave you, restate the missing pieces in one line, and proceed. Do not interrogate a user who has already done the work. A complete brief is a gift; reading past it is a tax on the user.

The eight inputs:

1. What is the one thing this copy must do? Sell a product, book a demo, change a belief, get a click. One thing. Not three.
2. Who is the reader? Not a demographic. A specific person with a specific problem and a specific moment. The person standing at the bus stop, not "urban millennials."
3. What does the reader currently believe? What does the copy need to shift? Name the Schwartz awareness level (unaware, problem-aware, solution-aware, product-aware, most aware): it picks the headline category and the lead type. See references/frameworks.md.
4. What is the promise? A real, specific benefit. Not "enhanced productivity." "Two hours back every Tuesday morning."
5. What is the proof? Numbers, demonstrations, comparisons, expert testimony, user quotes, guarantees. Copy without proof is opinion.
6. What is the format constraint? Billboard glance (3 seconds), magazine spread (8 seconds), homepage hero (5 seconds before scroll), long-form email (60 seconds if the hook lands).
7. What is the brand voice? If the user has a voice guide, follow it. If not, pick from the fifteen voices in references/voice-bank.md (Voices 13 to 15 are native Spanish registers), name your pick back to the user, and proceed. "I am writing this in Voice 1 (dry confident) blended with Voice 8 (founder narrator). Tell me if you want a different lever."
8. What is the call to action? What happens after they read this?

If any of these is missing and you cannot infer it, ask. One question per gap. Do not write past a hole.

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The Research Pass: When the Product Is Real, Look Before You Write

The tradition this skill draws on starts with research, not with writing. Hopkins worked the factory floor; Ogilvy read the Rolls-Royce engineering notes until he found the electric clock. When the product, brand, or competitor is real and you have tools to look, look.

What to fetch, in order of value:

1. The current landing page or listing. What the brand says today is the baseline the new copy must beat, and the source of voice you may need to hold.
2. Voice-of-customer language. Reviews, support threads, forum posts, sales call notes the user can share. Copy the reader's exact phrases for the problem, the fear, the outcome. A verbatim "I just wanted something that wouldn't break in six months" outperforms anything you invent. See the mining method in references/frameworks.md.
3. The competitors' headlines. You need to know what the reader has already heard to judge market sophistication (Schwartz) and to make sure your line could not run under their logo.

Two rules. First, research informs the copy; it never enters the copy unverified. A review quote is a source for language, not a publishable testimonial, unless the user confirms rights and accuracy. Second, keep it proportional: a billboard brief for a fictional brand needs no research; a sales page for a live product deserves ten minutes of it. When you cannot fetch (no tools, no access), ask the user for the landing page text and two or three real reviews instead.

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The Idea Pass: Find the Idea Before You Write the Words

This is the part most copy skips. It is also why most copy fails.

An idea is not a headline. An idea is the thing the reader walks away believing or feeling. The headline is one possible expression of the idea. Different ideas produce different headlines. Different headlines for the same idea are interchangeable.

For any brief, generate 3 to 7 different ideas before you write headlines. Each idea should be one sentence:

• The idea is that this product makes you the kind of person who notices the small things.
• The idea is that everyone else's solution treats the symptom; we treat the cause.
• The idea is that the reader has been lied to for years and we are the first to admit it.
• The idea is that this is so obvious it is embarrassing nobody did it before.

Then pick. Run each candidate through four questions and keep the one that survives the most of them:

1. Does it meet the reader where they are? It speaks to the awareness level named in the brief, not to the level the brand wishes the reader had.
2. Could the competition sign it? If a competitor could run the same idea under their logo, it is positioning wallpaper, not an idea.
3. Does it survive the billboard test? One line, no body copy, and the reader still gets it. If it cannot, the idea is not yet sharp enough.
4. Is it slightly uncomfortable to publish? Ideas that feel completely safe usually read as invisible. The best idea in the set tends to be the one the brand would hesitate over for a second.

Only then start writing headlines for it.

See references/craft.md for how the D&AD greats find ideas.

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The Headline Pass

Five times as many people read the headline as read the body. Most of the work is here.

Start from the awareness level named in the brief: it narrows which categories can work before you write a word (the mapping table is in references/frameworks.md). A most-aware reader wants the offer in the headline; an unaware reader needs the indirect or the reframe. Then generate.

Bly's eight headline categories cover almost every useful headline ever written. Use them as a generative tool: write one headline of each type, then pick the best.

1. Direct states the offer plainly. "Pure Silk Blouses. 30 percent off."
2. Indirect provokes curiosity, withholds the punchline. "How to win friends and influence people."
3. News announces something new or newly relevant. "Introducing the silent dishwasher."
4. How-to promises a method. "How to write a sentence that gets read."
5. Question names the reader's problem as a question. "Do you make these mistakes in English?"
6. Command tells the reader what to do. "Try it for a week. Decide for yourself."
7. Reason-why promises a list of reasons. "Seven reasons why a Volvo lasts longer."
8. Testimonial puts the proof in the headline. "I never read The Economist. — Management trainee. Aged 42."

For blog posts, paid social, and modern direct response (see references/frameworks.md for the full versions):

• Listicle a number naming a finite list. "Seven mistakes that cost CFOs an hour every Tuesday."
• Negative what not to do or buy. Patagonia: "Don't buy this jacket."
• Outcome-first the result is the headline. "From 0 to $40,000 MRR in 90 days."

For OOH and print, also try:

• Visual-completion the headline only works with the image. The line says "Lemon." The image is a perfect-looking Volkswagen.
• Self-deprecation the brand tells a truth against itself. Avis: "We're number two. We try harder."
• Compression the entire idea in three or four words. Nike: "Just do it." Stella Artois: "Reassuringly expensive."
• Reframe redefining the category. 7Up: "The Uncola."
• Object-as-headline the product itself, used or placed in a way that becomes the headline. Penny (Cannes 2025): printed the price directly onto the packaging.

Apply the 4 U's to every candidate headline:

• Useful does it offer something the reader wants?
• Urgent is there a reason to act now or keep reading?
• Unique is it specific to this product, not interchangeable with a competitor's ad?
• Ultra-specific does it use real numbers, real names, real details?

A good headline scores at least 3 of 4 strongly. A great one hits all 4.

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The Body Pass

Body copy is permission. The reader gave you permission by reading the headline. Earn the next sentence.

Three principles, in order:

1. The lead does most of the work after the headline. First sentence either earns the second sentence or loses the reader. No warm-up. No "in today's world." Open at speed. See references/frameworks.md for Bly's six lead types.

1. Argue in a line that flows. Each sentence should make the next sentence feel inevitable. The reader should not be able to stop. This is what D&AD copywriters mean by "the slippery slope."

1. Specificity is the proof. "It is quiet" is opinion. "At sixty miles an hour the loudest noise comes from the electric clock" is proof (Ogilvy, Rolls-Royce, 1958). Replace every adjective with a fact.

Length follows function. A billboard is seven words or fewer. A sales email is 300 words. A magazine long-copy ad is 1,200 words. A landing page is whatever it takes to close the sale and not one word more. Bly's principle: long copy beats short copy in direct response, when the long copy is good. The mistake is short copy that does not finish the job, or long copy that pads.

For long copy, the architecture matters. See references/frameworks.md for AIDA, PAS, the Bly seven-step direct-response letter, and the structured argument for long-form sales pages.

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The Offer Pass

In direct response, the offer outsells the words. Before writing the CTA, check that there is an offer worth calling to. Four components, each built deliberately:

1. The deal itself. What exactly do they get, at what price, on what terms? Vague offers convert like vague promises. "Start your free trial" is weaker than "14 days free, full plan, no card."
2. The guarantee. Take the risk off the buyer. Specific beats general: "60 days, full refund" beats "satisfaction guaranteed." Strongest of all is a guarantee tied to the promise itself: "If it does not save you three hours on the first Tuesday, do not pay."
3. Honest urgency. A real deadline, a real capacity limit, a real price change, stated plainly, moves the undecided. Invented urgency burns the brand for every future ad. If there is no honest urgency, do not manufacture one; let the guarantee carry the close.
4. Bonuses, named and valued. A bonus works when it solves the next problem the buyer will hit: the cold email course that ships with the follow-up sequence templates. A pile of unrelated extras reads as padding and cheapens the core offer.

If the brief has no offer beyond "buy it," say so. Proposing a stronger offer (a trial, a guarantee, a bundle) is often worth more than any rewrite of the headline. Put the proposal in Notes; the user owns pricing.

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The CTA Pass

A weak CTA loses sales the rest of the copy earned. A good CTA continues the promise.

Core rules

• Action verb plus what they get. "Get the free guide" beats "Submit."
• Mirror the language of the headline. If the headline promises "two hours back every Tuesday," the button can say "Get my Tuesday back."
• Reduce friction in the words. "Start free" reduces more friction than "Sign up."
• One primary CTA per page or per ad. Secondary CTAs are fine if they support the primary one.
• For direct response, restate the offer in the CTA area: what they get, what it costs, what the guarantee is, what happens next.

Verb bank by commitment level

Commitment increases left to right. Match the verb to where the reader is in their decision.

• Low (free, no card, browse). See. Read. Watch. Try. Browse. Start free. Take a look. Show me.
• Medium (sign up, trial, demo). Start the trial. Open an account. Book a 15 minute call. Get the demo. Reserve a spot.
• High (pay, buy, subscribe). Buy now. Subscribe. Get the plan. Upgrade. Order. Pay and start.
• Specific to category. Apply. Enroll. Donate. Pledge. Vote. Download. Install. Tell me when X ships.

Avoid generic verbs that match nothing: Submit, Click here, Continue, Learn more (as a CTA, not as secondary link), Next.

Microcopy under the button

A line of microcopy under the button reduces the last 10 percent of friction. Three patterns that work:

• Risk reversal. "No card up front." "Cancel any time." "60 day refund."
• Time anchor. "Takes 90 seconds." "Done in 4 minutes."
• Social anchor. "12,400 founders use Pulse." "Joined this week by 312 finance te

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Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: avectats7
• Source: avectats7/copy-that-sells
• License: MIT
• Homepage: https://github.com/avectats7/copy-that-sells

Install and usage instructions live in the source repository linked above.