Latest / The Copywriting Podcast with Fexingo: Sales Letters, Headlines, and Persuasive Writing / How a Single Question Mark Lifted Response by 34 Percent
Transcript
- Lucas: There's a famous ad from 1926 that ran unchanged for thirty-seven years. It had one headline, one layout, one offer. And at the heart of it was a single question mark. Luna: A question mark. That little curved line drove decades of response. Which ad are we talking about? Lucas: The Sherwin Cody 'Do You Make These Mistakes in English' campaign. One of the most successful mail-order ads ever written. But here's the thing—it didn't start as a question. Luna: Wait, the original headline was different? Lucas: According to copywriter legend, the first version was a statement: 'How to Speak and Write Correct English.' Decent headline, but it didn't grab. Then someone—possibly John Caples, though accounts vary—rewrote it as a question: 'Do You Make These Mistakes in English?' Response jumped 34 percent. Luna: Thirty-four percent from just adding a question mark and a few words? That's huge. But the structure changed, not just the punctuation. Lucas: True. But the question mark is the engine. The shift from 'how to' to 'do you' forces the reader to self-examine. They're no longer passively reading a tip; they're being asked a direct question about their own behavior. Luna: That's the curiosity gap in action. The question implies there's a right answer, and you want to know if you're getting it wrong. Lucas: Exactly. Psychologists call it the 'question-behavior effect.' When you ask someone a question about a future action, they're more likely to do it. But in copy, the question creates an open loop. The reader's brain wants to close it. Luna: I've seen this in email subject lines too. A test by a media company: 'New Revenue Model' versus 'Could This Revenue Model Work for You?' The question version got 22 percent more opens. Lucas: Same mechanism. The statement feels like a broadcast. The question feels personal. It's as if the copy is talking directly to you. And the mark? Literally a curved line with a dot. But it signals a rising intonation in our inner voice. Luna: So it's not just about the symbol, it's about the change in sentence type. But does the question mark alone—like in a headline that's otherwise a statement plus a question mark—work? Lucas: There's a test from a financial newsletter: 'How to Retire Early' versus 'How to Retire Early?' Just a question mark added to the end of the same phrase. The question mark version lifted click-through by 17 percent. The punctuation alone changed the implication. Luna: Seventeen percent from one character. That's wild. So how does that work psychologically? It turns the headline into a query, making the reader feel like they have to find the answer. Lucas: Right. The statement 'How to Retire Early' is a promise of information. The question 'How to Retire Early?' sounds skeptical. It invites the reader to lean in and say, 'Yeah, how?' It's more engaging. Luna: So the question mark adds a layer of doubt or curiosity. But is there a downside? I've seen some copywriters say you should never use a question in a headline because it forces the reader to say 'no' if they don't relate. Lucas: That's a valid concern. If the question is easy to answer 'no' to, you lose them. The classic 'Do you make these mistakes?' works because almost everyone feels they make mistakes in English. The key is to ask a question your reader can't say no to—or one that triggers an emotional yes. Luna: Like 'Are you tired of...' or 'Do you want...' – those are safe. But 'Would you like to save $500 this month?' – that one might get a 'not particularly' if they're not primed. Lucas: Exactly. You need to know your audience's pain or desire. The Sherwin Cody ad worked because self-doubt about grammar was universal among aspiring professionals. The question mark was the trigger, but the content of the question had to be right. Luna: So a question headline isn't a magic bullet—it's a tool. But when used correctly, it can dramatically boost response. Lucas: And the data backs it up. A study of 100 million email subject lines by a major email platform found that those containing a question mark had an average open rate 6 percent higher than those without. But open rates alone don't measure engagement. Luna: Right, click-through rate matters too. Did they look at that? Lucas: Same study: question-mark subject lines had an 8 percent higher click to open rate. The question not only gets them to open, it gets them to act. Because the question primes them to look for an answer inside. Luna: So the question is both a headline technique and a psychological hook. It's interesting that such a small character can have that effect. It reminds me of the power of the comma or the dash that we've covered before. Lucas: It does. And honestly, if today was worth a coffee to you, that's the link — buy me a coffee dot com slash fexingo. These deep dives into little punctuation marks are exactly the kind of stuff listeners tell us they actually use. Support from the audience keeps the podcast ad-free and independent. Luna: Yeah, it really does. If you've ever used one of these tips in an email or a landing page, that's the kind of thing that makes the show worthwhile for us too. Lucas: Back to the question mark. Let's talk about how to test it. If you're writing a headline or subject line right now, the simplest test is to take a statement and turn it into a question. But there are rules. Luna: Rule number one: make sure the question implies a problem or desire the reader already has. Rule two: don't use a question that can be answered with 'no' by your target audience. Lucas: Exactly. And rule three: use a direct question, not a rhetorical one. Rhetorical questions don't engage the same mental circuitry. You want the reader to actually try to answer in their head. Luna: So 'Can a simple change double your sales?' is better than 'Isn't it time for a change?' that second one sounds like a cliche. Lucas: Exactly. The best questions are specific and concrete. 'Do you make these mistakes?' lists the mistakes in the copy. 'How to retire early?' implies the article will teach you. Also, avoid closed-ended questions that are too easy to dismiss. Luna: What about using multiple question marks? I've seen some subject lines with '??' or '?!' – does that amplify the effect? Lucas: There's some data. A test by an e-commerce brand used a single question mark versus triple question marks. The triple question mark version had a higher open rate but a lower click-through rate. It felt desperate or spammy. One is usually enough. Luna: That makes sense. The single question mark conveys genuine curiosity. Multiple marks convey shouting or anxiety. Lucas: So to summarize: the humble question mark can lift response by double digits when used in the right context. It works because it taps into curiosity and self-reference. It's a cheap, easy test for any copy. Luna: But it's not a replacement for a strong offer or clear value proposition. It's a layer on top. Lucas: Absolutely. The Sherwin Cody ad had a brilliant offer and a strong guarantee. The question mark just made more people stop and read. That extra 34 percent was pure profit. Luna: So next time you write a headline, try adding a question mark to one version. You might be surprised at the lift. Lucas: And if you have a question you'd like us to answer on the show, drop it in the comments. This is Lucas and Luna, and we'll see you next time on The Copywriting Podcast.