Latest / The Email Marketing Podcast with Fexingo: Newsletters, Open Rates, and Subscriber Growth / Why Email Copywriting Style Drives Subscriber Trust
Transcript
- Lucas: There's this stat that's been rattling around my head. Litmus and HubSpot did a joint study in 2025 — they analyzed over 100 million email sends — and found that brands using a consistent, conversational voice in their copy saw a 28 percent higher click to open rate than brands using formal or promotional language. Luna: Twenty-eight percent is huge. That's not just a tweak, that's a strategy shift. Lucas: Exactly. And the thing is, most marketers I talk to obsess over design — templates, hero images, button colors. But the study showed that copy style actually predicted subscriber trust better than layout. Luna: So the words matter more than the wrapper. Which makes sense when you think about it — we scan design in milliseconds, but we process voice over a few seconds. Lucas: Right. And that voice is what builds or erodes trust. Let me give you a concrete example. Netflix. Their email team does something interesting. They have a core brand voice — helpful, slightly witty, personal — but they stretch it depending on the segment. Luna: I've noticed that. For a new user, they might say 'Start your free trial — because your next obsession is waiting.' But for a long-time binge-watcher, it's more like 'You finished The Diplomat in two days. Here's what to watch next.' Lucas: Exactly. That second one is conversational, almost like a friend who's been paying attention. And it works because the voice is consistent — informal, direct, benefit-oriented — even though the content changes. They're not switching to a formal 'Dear valued subscriber' for the long-time user. That would break trust. Luna: Which brings us to what's called brand voice elasticity. How far can you stretch your tone for different segments before it stops feeling like the same brand? Lucas: That's the key question. And the Litmus-HubSpot study gives us a clue. They found that the biggest drop in click to open rate happened when brands switched from a conversational tone to a formal one within the same campaign series. So consistency across touchpoints matters more than the specific tone you pick. Luna: So you could be playful for your social media crowd and more direct for your B2B buyers, as long as the underlying personality — the word choices, the sentence rhythm — stays recognizable. Lucas: Yes. And that's harder than it sounds because most brands don't have a documented voice guide for email. They have a style guide for the website, maybe for social, but email often gets treated as an afterthought. So the copy ends up sounding like it was written by three different people. Luna: I've seen that happen. A brand I worked with had a very playful Instagram voice — lots of emoji, short sentences, pop culture references. But their emails were dry and corporate. Subscribers would comment on social saying 'your emails are boring' — that's a disconnect. Lucas: And that disconnect costs you. The study also looked at unsubscribe rates. Brands with a consistent email voice had 12 percent lower unsubscribe rates than those with high variance. Not massive, but meaningful over a year. Luna: Twelve percent compounded. If you're sending weekly, that's a lot of subscribers you keep. Lucas: Right. So how do you actually build that consistent voice? Let me walk through a framework I've seen work. First, define your core brand personality in three adjectives. Not 'professional, innovative, reliable' — that's useless. Something like 'curious, direct, slightly irreverent.' Luna: Then test those adjectives against your emails. Does each sentence sound like someone who's curious? Or is it just stating facts? Lucas: Exactly. Second, write a sample email for your most common trigger — say, a welcome series — in that voice. Read it out loud. If it sounds like how you'd talk to a smart friend, you're on the right track. If it sounds like a press release, rewrite it. Luna: Third, create a 'do and don't' list for email specifically. Do use contractions. Don't use jargon like 'leverage' or 'synergy.' Do start with a subject line that sounds like a human wrote it. Don't start with 'We are excited to announce.' Lucas: That's gold. And then — this is the part most people skip — you need to train your team. Not just the copywriter, but the designer, the product manager, the compliance person. Everyone who touches email should have a one-page voice cheat sheet. Luna: At my last company, we did a quarterly 'voice audit' — we'd pick five recent sends and read them out loud as a team. We'd flag any sentence that felt off-brand. It was awkward at first, but after two quarters, the copy was noticeably better. Lucas: I love that. And it ties back to the data. The study found that brands that do regular voice audits see a 15 percent lift in click to open within six months. So it's not just fluff — it has measurable ROI. Luna: But let me push back on one thing. Isn't there a risk that consistency becomes boring? That subscribers get used to your voice and start tuning it out? Lucas: That's a fair concern. And the answer is: consistency doesn't mean monotony. Think of it like a musician's style. Miles Davis always sounded like Miles Davis, but every album was different. The voice is the instrument; the content is the song. Luna: So you can vary the subject line structure — sometimes a question, sometimes a statement, sometimes a one-word teaser — as long as the word choice and rhythm stay consistent. Lucas: Exactly. And you can test different tones within your voice. For example, a brand like Patagonia has a consistent voice — activist, straightforward, appreciative of nature. But they can send an email about a sale in that same voice, or an email about a climate petition. The tone shifts slightly, but the personality is unmistakable. Luna: That's the elasticity we talked about. And it's hard to get right. I think a lot of marketers default to being too formal because they're afraid of offending someone. But the data says the opposite — being too formal actually hurts engagement. Lucas: The study backs that up. Emails written at a Flesch-Kincaid grade level of 6 to 8 — that's around middle school reading level — had higher click to open rates than those at grade 10 or above. Conversational language wins. Luna: So write like you talk. But edited. Not a transcript. Lucas: Exactly. And that brings me to a practical tip: read your draft out loud. If you stumble on a sentence, your subscribers will too. Simplify it. Luna: Okay, but what about transactional emails? Those feel like they have to be formal — order confirmations, password resets, shipping updates. Can you bring voice into those? Lucas: Absolutely. And this is where a lot of brands miss an opportunity. A great example is a company called Bombas, the sock company. Their shipping confirmation email says something like 'Your socks are on their way — and we promise they're worth the wait.' It's short, conversational, and still conveys the necessary info. Luna: And it makes you smile. Which builds affinity. That's a trust deposit. Lucas: Right. And those deposits add up over time. The study measured a 'subscriber trust score' based on engagement patterns and found that a consistent voice was one of the top three predictors, alongside send frequency and list hygiene. Luna: So if you're focusing only on list cleaning and frequency caps, you're leaving a lever on the table. Copy style is cheap to change and has a big impact. Lucas: Cheap in terms of money, but it requires discipline. You can't just write one good email and call it done. You need a system. Luna: And a willingness to edit ruthlessly. I've seen drafts where every sentence starts with 'We' — 'We are pleased to offer,' 'We think you'll love.' That's a red flag. Shift to 'You' — 'You'll love this,' 'Here's what you need.' Lucas: That's actually one of the easiest fixes. The study found that emails with a higher ratio of 'you' to 'we' had significantly higher click to open rates. It's called the 'you-centric' principle. Luna: And it's not just about pronouns. It's about framing every benefit around the subscriber's world, not the brand's. Lucas: Exactly. Let me give you one more number. The study also tracked 'brand recall' — asking subscribers to name the sender of an email they opened. Brands with a distinct, consistent voice had 34 percent higher recall than those with a generic tone. Luna: That's huge in a crowded inbox. If someone can't remember who sent the email, they're not going to click. Lucas: So the takeaway is: invest in your voice. Write a guide. Train your team. Audit your sends. It's not a one-time project — it's a continuous discipline. But the data says it's worth it. Luna: Honestly, if today's episode sparked an idea you actually use in your next email, that's the kind of thing that makes this podcast worth doing. If that resonated, you can support the show at buy me a coffee dot com slash fexingo. It's a small gesture that keeps us ad-free and focused on the data. Lucas: Yeah, we really appreciate that. And it helps us keep digging into studies like this one. So thank you. Luna: Alright, back to the data. Lucas, you mentioned voice audits earlier — what's the simplest way to start one if you've never done it? Lucas: Pick your last ten sends. Read the subject line and first sentence of each. Ask yourself: if you covered up the brand name, would you know who sent it? If the answer is no for more than two of them, you have a consistency problem. Luna: That's a quick gut check. And then what? Rewrite the worst ones in your target voice, and use those as templates. Lucas: Exactly. And then share those rewrites with your team. Say 'This is what our voice looks like. Write everything in this direction.' Over time, it becomes muscle memory. Luna: I want to caution against one thing though — don't let voice become a straitjacket. If your brand voice is 'witty' but you're sending a serious security alert, wit might backfire. Elasticity means knowing when to dial it back. Lucas: Great point. The study actually found that brands that matched their tone to the context — serious for security alerts, playful for promotions — had higher trust scores than those that used the same tone everywhere. So consistency isn't rigidity. Luna: It's a spectrum. You have a core, and you flex within that core. Lucas: And the best way to figure out where that spectrum is? Test. A/B test subject lines with different tones. Test opening sentences. The data will tell you where your subscribers' sweet spot is. Luna: Alright, so to wrap up: voice is a lever. It costs nothing but thoughtfulness, and it can move open rates, click rates, and trust. Start with a three-adjective personality, write a one-page guide, and read your drafts out loud. Lucas: And remember: your subscribers are smart. They can tell when you're being authentic versus when you're reading from a script. That difference is exactly what the data is measuring. Luna: Thanks for listening, and we'll see you next time.