Latest / The Copywriting Podcast with Fexingo: Sales Letters, Headlines, and Persuasive Writing / How a One-Word Change Tripled Direct Mail Response
Transcript
- Lucas: So there's this old direct mail test — 1970s, a food company selling a new line of frozen dinners. They ran two versions of the same sales letter. Only one word differed in the headline. Luna: One word. And it made a measurable difference? Lucas: It tripled response. The control headline said something like 'Enjoy Delicious Frozen Dinners Tonight.' The test version said 'Enjoy Crisp Frozen Dinners Tonight.' One word swap — 'delicious' to 'crisp.' That's it. Luna: I can already feel why that worked. 'Delicious' is so generic, right? Every food ad uses it. Lucas: Exactly. 'Delicious' is what copywriters call a 'puff' word — it's an opinion, not a fact. The reader's brain barely registers it. But 'crisp' is specific. It evokes texture, sound, even temperature. You can almost hear the crunch. Lucas: And by the way, if these kinds of copywriting experiments spark ideas you've actually used in your own work — that's exactly why this show stays ad-free. If today's episode was worth a coffee to you, the link is buy me a coffee dot com slash fexingo. No pressure, just a small way to keep these deep dives coming. Luna: Yeah, it's a tiny gesture that makes a huge difference for us. And honestly, every bit of support goes straight into more research and testing so we can bring you better examples. Lucas: So back to that frozen dinner test. The copywriter, I think it was a guy named Bob Hacker, he later explained the logic. He said, 'Delicious is a claim. Crisp is a promise.' And that distinction is everything. Luna: A claim versus a promise — I love that. A claim you can argue with. A promise you can verify. Lucas: Right. When you read 'crisp,' your brain instantly runs a simulation. You've bitten into something crisp before — you know the sensation. That simulation activates a stronger emotional response than the abstract concept of 'delicious.' Luna: It's almost like the word itself becomes a mini sensory experience. There's research on this — concrete nouns and adjectives trigger more neural activity than abstract ones. Lucas: There's a famous study from the 1980s where they showed people words like 'dog' and 'table' vs. 'justice' and 'truth.' The concrete words lit up more areas of the brain. And that's what you're doing with copy — you're trying to light up the reader's brain, not just inform it. Luna: So how do we apply this beyond frozen dinners? Like, what's the modern equivalent in email subject lines or landing pages? Lucas: Great question. Let's take a B2B example. You're selling a project management tool. You could write 'Improve Team Productivity' — which is abstract, overused. Or you could write 'Stop Losing Tasks in Email Threads' — which is concrete, specific, and emotionally charged. Lucas: The second one paints a picture. The reader has been there. They know the frustration. And the word 'stop' adds a sense of urgency. Luna: And you can test that. Actually, I remember a case from MarketingExperiments where they changed a headline from 'Get Better SEO Results' to 'Get 40% More Organic Traffic in 30 Days.' The specific number boosted conversions by 85 percent. Lucas: That's the same principle — specificity creates credibility. 'Better' is a weasel word. '40% more in 30 days' is a verifiable claim. Even if the reader doubts it, they're more likely to click because it sounds like a real offer. Luna: But there's a risk, right? Being too specific can backfire if you can't deliver. What if the promise is too precise and you miss the mark? Lucas: Absolutely. If you promise '40% more traffic in 30 days' and the reader gets 20%, you've broken trust. So specificity has to be grounded in truth. But within that constraint, you can still find the most concrete, sensory, or numeric version of your message. Luna: So it's a balance. You want specific enough to trigger a response, but not so specific that you're painting yourself into a corner. Lucas: Exactly. And there's a simple editing trick to find those words. After you write a draft, go through and circle every adjective. Then ask yourself: is this a puff word or a specific word? If it's a puff, replace it with something that appeals to one of the five senses. Luna: Or a number. Numbers are a kind of specificity too. 'Fast shipping' becomes 'Free shipping in 2 days.' Lucas: Right. And let's go back to that original test for a second. The frozen dinner headline — it wasn't just about the word 'crisp.' It also changed the reader's expectation. 'Delicious' is about taste. 'Crisp' is about texture. That shift from one sense to another can be powerful. Luna: I wonder if the same word swap would work today, in 2026. Like, would 'crisp' still outperform 'delicious' in a modern A/B test? Lucas: Probably yes, because the psychology is timeless. But I'd love to see a replication with a modern audience. The medium changes, but the brain doesn't. Luna: So what's your takeaway for our listeners? The one thing they can do after this episode? Lucas: Next time you write a headline, a subject line, or even a call to action, pick the most concrete word you can. Don't say 'great.' Say 'fast' or 'quiet' or 'bright.' If you can make it sensory, even better. And then test it. That one word could be the difference between a letter that gets tossed and a letter that gets a response. Luna: One word. It's almost too simple to believe — but the data is there. Lucas: It's the kind of thing that makes copywriting endlessly fascinating. Small changes, big results. And as we've seen, that principle has worked for decades and still works today.