Latest / The Copywriting Podcast with Fexingo: Sales Letters, Headlines, and Persuasive Writing / How a Typo Made a Direct Mail Campaign Profitable
Transcript
- Lucas: So there's this direct mail fundraising letter that went out in 2019 for a mid-sized environmental nonprofit. The control was a beautifully written, professionally copyedited letter — the kind that had been through four rounds of review. It pulled a 2.1 percent response rate, which was respectable for that donor segment. Luna: Okay. And the test variant? Lucas: The test variant was identical — same headline, same body copy, same call to action — except for one thing. In the opening paragraph, the word 'environmental' was misspelled as 'enviromental'. Missing an 'n'. That was the only change. Luna: Wait — they deliberately sent out a letter with a typo? That feels like a rookie mistake. Lucas: It feels like one, but the result was a 2.9 percent response rate — a 38 percent lift. And average gift size was actually slightly higher, too, by about 6 percent. So not only did more people respond, but they gave a bit more on average. Luna: That is wild. What's the explanation? Did they test it multiple times? Lucas: They ran it across three mail drops — spring, summer, fall — with different list segments. The typo variant outperformed the control in every single drop. The lift ranged from 29 percent to 44 percent. So it wasn't a fluke. Luna: Okay, so what's the psychology here? Because my first reaction is that a typo makes the organization look sloppy, not trustworthy. Lucas: Right, and that's the intuitive reaction. But there's a well-studied phenomenon in behavioral science called the 'fluency effect' — or, in this case, the disfluency effect. When something is too polished, too smooth, readers process it effortlessly — but they also sometimes subconsciously distrust it. It feels like it was written by a PR committee. Luna: So a small imperfection makes it feel more human, more authentic? Lucas: Exactly. A typo signals that a real person wrote this, not a corporate machine. It triggers a slightly slower, more deliberate reading — disfluency — which actually increases cognitive engagement. The reader pauses, registers the error, and that moment of processing can make the message feel more genuine. Luna: But there's a fine line, right? One typo might feel authentic. Ten typos and you look like you don't care. Lucas: Absolutely. The key is that the typo has to be minor — a single-letter omission, a transposition, something that doesn't change meaning or sound like a different word. And it has to appear in a place that feels natural, not in the headline or the call to action. You don't want a typo in your offer headline. Luna: So where did they put it in this letter? The opening paragraph? Lucas: Yes, the second sentence of the opening paragraph. 'As an organization dedicated to protecting our enviromental heritage…' — that 'enviromental' hit right there. The rest of the letter was pristine. And the typo was consistent across all three mailings — same error, same spot. Luna: I wonder if the effect is partially that readers feel smarter for catching the mistake. Like, 'Oh, I spotted an error, I'm paying attention.' Lucas: That's actually a theory that's been tested. In one study, readers who noticed a minor typo in a persuasive message reported higher agreement with the message than readers who didn't notice it. The act of noticing gave them a small ego boost, which then transferred to a more favorable view of the content. Luna: So the typo becomes a subtle engagement device. That's a fascinating reframe. Lucas: It is. And it's not just for fundraising. There's a famous case from the early 2000s where a software company sent a sales letter with a deliberate typo in the P.S. — 'We look forward to hearing form you' — and that version outperformed the corrected version by 16 percent. Same principle. Luna: But I've also seen tests where a typo hurt response. What separates the successes from the failures? Lucas: Great question. In my research, the failures share two traits. First, the typo appears in a high-stakes location — the headline, the call to action, or the price. If you misspell a dollar amount, readers lose confidence. Second, the typo makes the copy look genuinely sloppy — multiple errors, inconsistent style, or a misspelling of the organization's own name. That destroys trust. Luna: So it has to feel like a one-off mistake, not a lack of quality control. Lucas: Exactly. The typo should be believable as a human oversight, not a systemic problem. And it helps if the overall design and production quality are high — nice paper, good printing, professional layout. That contrast makes the typo stand out as an anomaly, not the norm. Luna: Did the nonprofit in this case know they were testing a typo? Or was it an actual mistake they decided to keep? Lucas: It was intentional. The copywriter had read about the disfluency effect and convinced the development director to run a split test. The development director was skeptical — her first reaction was the same as yours — but she agreed to a small test. After the first mailing showed a lift, they expanded the test to the other drops. Luna: So what happened after the campaign? Did they keep using the typo? Lucas: They actually tried to replicate the effect in a different mailing the following year — different offer, different list. But the typo this time was in the body copy, and the control was a slightly different version. The lift was only 4 percent, not statistically significant. So the effect isn't guaranteed every time. Luna: That's important. It's not a magic bullet. It's a tactic that works under specific conditions. Lucas: Right. And I think the broader lesson isn't 'add a typo to every letter.' It's that perfection can be a liability in persuasive writing. When everything is too smooth, readers become skeptical. A small, deliberate flaw can signal authenticity and increase engagement — but only if it's done with care and testing. Luna: It reminds me of something I heard about handwritten notes — that a slightly messy script feels more personal than perfect calligraphy. Lucas: Exactly the same principle. Imperfection signals humanity. And in a world where most marketing is highly polished, a little roughness can stand out. Luna: If these kinds of marketing insights are something you've found useful in your own work — maybe a test you ran or a campaign you adjusted — it's part of why we keep this show ad-free. We want to share what actually works, not what a sponsor wants you to hear. If you'd like to support that, you can buy us a coffee at buymeacoffee dot com slash fexingo. No pressure at all — just a way to keep the conversations going. Lucas: Appreciate that, Luna. And I'd add that the listener community has been a huge source of ideas for episodes — we've had several topics suggested by people who listen, and we've tested some of them ourselves. So that support really does feed back into the show. Luna: Yeah, absolutely. Alright, so back to the typo — one more thing. Is there any risk that the typo could backfire if the recipient is a stickler for grammar? Lucas: There's always that risk. Some people will see any typo as a sign of incompetence. But in the tests we've seen, the segment that responds negatively is small — usually under 5 percent of the audience. And the lift from the majority who respond positively more than compensates. So it's a net positive, but it's not universal. Luna: So the copywriter's job is to know the audience. For a conservative donor base — say, older, traditional — a typo might hurt more than help. Lucas: Exactly. Audience matters. The environmental nonprofit's donor base was younger and more progressive — the kind of people who value authenticity over polish. That demographic is more forgiving of minor errors. So the tactic fits their psychographic profile. Luna: That's a good reminder. Copywriting isn't about rules — it's about understanding the reader's expectations and using them. Lucas: Right. And that's why testing is so important. The typo effect is real, but it's not a one-size-fits-all solution. Test it, measure it, and let the data decide. Luna: Alright, so to wrap up — we've got a specific tactic: a single, deliberate typo in a low-stakes location, in an otherwise polished piece, can boost response by making the message feel more human. But test it, know your audience, and never put the typo in the headline or the call to action. Lucas: That's the nutshell. And if you're looking to shake up a stale control, it's a fairly low-risk test to run. The cost of adding a typo is zero — the potential upside is real. Luna: Thanks, Lucas. That was a fun one. I'm going to look at my own copy with fresh eyes — maybe a little less perfect. Lucas: That's the spirit. Until next time.