Latest / The Copywriting Podcast with Fexingo: Sales Letters, Headlines, and Persuasive Writing / How One Underlined Sentence Increased Donations 400 Percent
Transcript
- Lucas: So there's this fundraising letter that went out in 1997 from a small nonprofit. Total budget for the campaign was about thirty thousand dollars. And it ended up pulling in something like twelve million over the next eighteen months. Luna: Okay, that's a massive return. Was it a famous appeal? Like the one from the Nature Conservancy or something? Lucas: Close. It was from a group called the American Foundation for the Blind. But the fundraiser who wrote it — a guy named Jerry Huntsinger — later revealed the one weird tweak that he believed made the difference. And it wasn't the headline, wasn't the P.S., wasn't even the offer. Luna: Let me guess. A handwritten underline? Lucas: Bingo. Specifically, he took a pen and drew a single underline beneath one sentence in the body copy. The sentence said: 'Please send whatever you can.' Luna: Just that sentence? Not the ask amount, not the urgency line? Lucas: Just that. And here's the thing — that letter had been mailed without the underline in a previous test. It did fine, maybe a one and a half percent response. But with the underline on that sentence, the response jumped to over six percent. Four times the donations. Luna: That's wild. But was it really the underline, or could it have been a different list, different timing? Lucas: They controlled for that. Same list, same month, same outer envelope. The only variable was that one handwritten underline. Huntsinger said he did it almost as an afterthought — he wanted to simulate what a real donor might do if they were reading and wanted to emphasize a line for the next person. It made the letter feel like a personal note. Luna: So it's not just visual emphasis — it's a social signal. Someone else cared enough to mark this, so maybe I should pay attention. Lucas: Exactly. There's a psychological principle called 'cognitive ease.' When you see something that breaks a familiar pattern — like a handwritten mark on a typed page — your brain slows down and processes it more deeply. You're no longer skimming. You're actually reading that sentence. Luna: And in a fundraising letter, that pause can be the difference between tossing it and writing a check. Lucas: Right. But here's the nuance — it only works if the sentence itself is already a strong appeal. If you underline a weak line, you're just highlighting the weakness. Huntsinger tested underlining 'Please give generously' and got no lift. But 'Please send whatever you can' — that's a permission structure. It lowers the barrier. The underline tells the reader, 'This part is safe to trust.' Luna: So it's like a cognitive shortcut. The underline functions as a trust signal. Lucas: Yes. And it's not just mail. Think about email. Have you ever noticed that some nonprofit emails will put one sentence in bold or in a different color? That's the digital version of the underline. Wikipedia's donation banners do this constantly — one sentence like 'If everyone reading this donated $3, our fundraiser would be done in an hour.' That sentence is often underlined or bolded. Luna: But in digital, underlines usually mean hyperlinks. You have to be careful — people might click expecting a link and get annoyed. Lucas: Great point. So in email, underline works best in plain text messages where it clearly isn't a link. In HTML emails, bold or a different font color is safer. But the principle holds: one visual deviation in a long block of text acts as a spotlight. Luna: Right. And that goes back to something you said earlier about pattern break. If everything is bold, nothing is bold. Lucas: Exactly. The underline works because it's rare. In a typical direct-mail letter, you see maybe three or four underlined sentences total. If you underline a dozen, the effect disappears. Your brain just treats it as part of the layout. Luna: So what's the modern analog for, say, a landing page or a sales page? Lucas: One word: the call to action button. That's the one element you want the eye to land on. But I think we can learn from this technique by adding a subtle visual cue just before the CTA. Like a handwritten arrow, or a star, or a short sentence in italics that says 'This matters.' Some of the highest-converting pages I've seen use a single sentence in a quotation marks or a different color that acts as the underline. Luna: And it has to be the right sentence. Not the headline, not the testimonial, but the one line that removes the final objection. Lucas: Right. In Huntsinger's case, the objection was 'I can't give a lot, so why bother?' The underlined line said 'Please send whatever you can.' That directly answered the objection. Underline, boom — permission granted. Luna: I think this also points to something bigger about how we process persuasion today. With all the noise, we're all skimming. The only copy that breaks through is the copy that looks different. Lucas: Absolutely. And the bar for 'different' is getting lower. A handwritten underline in a sea of typed text used to be a huge contrast. Now, in an inbox full of graphics, a plain-text email with one underlined sentence can feel refreshing. That's still pattern break. Luna: So the lesson is: find the one sentence that matters most, and mark it. But mark it in a way that's contextually appropriate. Lucas: Right. And test it. Don't assume bold works better than underline, or red than blue. It's the deviation that matters, not the specific style. Luna: That's actually a really practical takeaway. I'm going to try this on our next donation appeal. Lucas: Speaking of which — if today's deep dive into that one underline was helpful, it's exactly the kind of concrete tactic we put into every episode. And the reason we can keep doing it without sponsors is listener support. If you've ever gotten a useful idea from this show, you can help us keep going at buy me a coffee dot com slash fexingo. Just the price of a coffee, and it really does add up. Luna: Yeah, it's how we stay independent. And we read every message, so if you have a copy question, that's a good place to drop it too. Lucas: Okay, back to the underline. One more thing — I want to mention a modern case where this was used brilliantly. The advocacy group SumOfUs sent out a fundraising email in 2020 with a single underlined sentence: 'If you can, please chip in $5.' The control had no emphasis. The underlined version beat it by 34 percent. Luna: Thirty-four percent lift from one underline. That's the kind of leverage that makes copywriting so fascinating. Lucas: Exactly. Small change, big result. And it cost them exactly zero dollars to implement. Luna: So the takeaway for everyone listening: go back to your last email or letter. Find the one sentence that, if the reader remembers only that, they'll take the action you want. Underline it. Then see what happens. Lucas: And if you do test it, let us know. We'd love to hear your results. That's it for today — thanks for thinking about copy with us.