Latest / The Copywriting Podcast with Fexingo: Sales Letters, Headlines, and Persuasive Writing / How a Six-Word Headline Beat a 500-Word Sales Letter
Transcript
- Lucas: So there's this legendary copy test from the early 1980s — one of those quiet experiments that should have changed everything but mostly got forgotten. Luna: Okay, I'm already curious. What was the test? Lucas: Two ads for the same product — a book on copywriting, actually. One was a classic long-copy direct-mail letter, around 500 words, written in the style that had been working since the 1920s. The other was a tiny display ad — maybe three inches tall — with exactly six words as the headline: 'Two Words That Sell Anything'. Luna: Wait — six words? That's the whole headline? No subhead? No body copy? Lucas: There was a tiny bit of body copy below it, maybe twenty words. But the whole ad was dwarfed by the letter. And here's the kicker: the six-word headline pulled more than double the response rate of the 500-word letter. Not slightly better — more than twice. Luna: That's wild. But what were the two words? The headline says 'Two Words That Sell Anything' — are those the two words, or are the two words in the body? Lucas: The two words were 'Free Book' — that was the offer. The headline teased that the book revealed those words. So the headline itself was a kind of puzzle — it made you lean in. 'Free Book' is an old offer, but the way it was framed — as a secret — that's what got the click. Luna: So the headline's job wasn't to sell the book. It was to sell the next sentence. Lucas: Exactly. And that's the real lesson from this test. A headline's only job is to get the first sentence read. The first sentence's job is to get the second sentence read. And so on. Most copywriters — then and now — try to do too much in the headline. They try to explain, persuade, close the sale. But the test shows that a headline that simply buys attention — with curiosity or a clear promise — can outperform one that tries to do the whole job upfront. Luna: It reminds me of that old John Caples line: 'The headline is the most important element of an advertisement. It should be written first, rewritten, and then rewritten again.' But most people stop at the first draft. Lucas: Caples is the right reference here. He ran similar tests in the 1930s — he found that changing a single word in a headline could double response. But what's interesting is that the industry never fully absorbed the lesson. Even today, when I look at landing pages for SaaS products, I see headlines that are basically mini-essays: 'The All-in-One Platform That Helps You Streamline Workflows, Boost Productivity, and Drive Team Collaboration in Real-Time.' That's not a headline. That's a feature list. Luna: And the data says the shorter one wins. But is that always true? I feel like there are situations where long copy works better — like for high-ticket items or complex B2B products. Lucas: Long copy absolutely works when the reader is already interested. But the headline still has to earn that interest. The classic example is the old Wall Street Journal ad — the headline is 'The Wall Street Journal. It Works.' That's four words. Then the copy is a long story about a businessman who gets ahead by reading the paper. The headline buys you the first paragraph. The first paragraph buys you the second. By the time you're three paragraphs in, you're invested. Luna: So the principle is: short to attract, long to persuade. But only if you've earned the right to be long. Lucas: Right. And that's where most copywriters go wrong — they assume the reader owes them attention. But attention is a scarce resource. Every headline is competing with a notification, a text message, a TikTok video. If your headline doesn't trigger a micro-commitment — a tiny mental 'huh, what's that?' — the reader scrolls past. Luna: I want to test this myself. Do you have a real modern example where this principle shows up? Lucas: There was an email subject-line split test I saw from a newsletter last year. The control was something like 'How to Get More Done in Less Time: The 5-Step Productivity System That Actually Works' — pretty standard, 16 words. The variant was 'The Productivity Lie' — three words. The variant had a 40% higher open rate and a 22% higher click-through rate. Luna: Three words. 'The Productivity Lie.' That's almost the same structure as 'Two Words That Sell Anything' — it teases a secret, creates curiosity, but doesn't try to explain everything. Lucas: Exactly the same structure. It's a curiosity gap. The reader thinks, 'Wait, what lie? Am I believing it? I need to know.' That micro-commitment is the whole ballgame. Luna: Do you think the principle extends beyond digital? Like, what about a print ad or a billboard? Lucas: Billboards are actually the purest test. You have maybe three seconds. The best billboard headlines I've seen are three to five words. The classic 'Got Milk?' — two words with a picture. Or that old Volkswagen ad 'Lemon' — one word. They don't explain; they stop you. Luna: But surely there's a risk of being too clever. If the headline is just cryptic, people might not bother. Lucas: That's the balance. You need a clear promise or a clear curiosity gap — but not confusion. 'Two Words That Sell Anything' works because you understand the promise: you'll learn something that helps you sell. It's not cryptic; it's mysterious in a useful way. 'Lemon' works because the image of a car with the word 'Lemon' creates a tension — you want to resolve it. But if the headline is 'The Answer Is Inside' with no context, that's just confusing. Luna: So the rule is: clarity plus curiosity. Clarity about what you're promising, curiosity about how you'll deliver. Lucas: That's a good way to put it. And the test we started with — the six-word headline — is the best proof I know. The 500-word letter actually had a stronger offer — it was a direct mail piece with a reply card. The tiny ad just had a coupon. But the headline did the heavy lifting. Luna: And if today's episode was useful to you and you want to keep it ad-free, buy me a coffee dot com slash fexingo helps. Lucas: Yeah, genuinely. It's a small thing that makes a big difference for us. Luna: Alright — back to the test. So the six-word headline doubled the response. Did anyone in the industry actually change their approach after that? Lucas: Not really. The test was published in a small direct-response newsletter. A few top copywriters — like Gary Bencivenga — talked about it. But most agencies kept writing long headlines because that's what clients expected. There's a lot of inertia in marketing. Luna: It's fascinating that the data was there and people just ignored it. What's your advice for someone writing a headline tomorrow? Lucas: Write the headline first. Spend as much time on it as you do on the body. Then cut it in half. Then cut it again. If you can say it in six words, don't use seven. And test it — run a cheap Facebook ad with two headlines and see which one gets the click. The data will tell you fast. Luna: And if you're writing a longer piece — like a sales letter — do you still lead with a short headline? Lucas: Absolutely. The headline is the gate. Once the reader is through, you can take your time. But the gate has to be narrow. The most effective sales letters I've studied — the ones that ran for years — all have headlines that are five to ten words max. The classic 'They Laughed When I Sat Down at the Piano' — nine words. 'How I Made a Fortune With a Simple Idea' — nine words. Short, specific, curious. Luna: And they all have that element of story or secret. 'They Laughed' — that's social proof and conflict. 'Made a Fortune' — that's greed. 'Simple Idea' — that's ease. They hit multiple triggers in very few words. Lucas: Right. And they don't try to be clever for clever's sake. They're direct. I think that's the biggest lesson from the six-word headline test: be direct about the benefit, but leave a little mystery about how it works. The reader wants to close the gap. Luna: I'm going to try that with my next email. Instead of 'Here Are 5 Tips for Better Sleep,' I'll do 'The Sleep Mistake You're Probably Making.' Lucas: That's exactly the structure. Let me know how it performs. I'd bet the open rate jumps. Luna: I will. And I'll report back. Lucas: One more thing: the test also shows that the offer matters. 'Free Book' is a strong offer — it's zero risk, high perceived value. If the offer is weak, no headline can save it. But a great headline multiplies a strong offer. Luna: So it's a combination: the right promise in the headline, the right offer underneath. Lucas: Exactly. And that's the art. The science is testing. But the art is knowing which promise will resonate — and capturing it in as few words as possible. Luna: I think I need to go rewrite my homepage headline now. Lucas: If it's longer than ten words, yes. And if you start with 'Welcome to' — definitely.