The Sales Psychology Behind Subject Lines That Get Clicks
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Recently, a biz pal of mine posted on Threads asking how people come up with their subject lines. Naturally, I slid into her DMs and proceeded to leave her wayyyy more information than was needed to help her out.
When I came up for air, I realized I'd basically recorded a podcast episode in someone's inbox.
So here we are. You can check out the podcast at the links here, or read my subject line tips below!
If you write your own sales emails and then sit there staring at the subject line field, this post is for you. We're talking about:
the psychology behind what makes people open emails
the tactics I use personally
and the mistakes that are killing your open rates without you even realizing it
But reader, beware! You may just increase your open rate by reading this!!
What a Subject Line Has to Do
The job of a subject line is to get your email opened.
But there's a second layer: it has to make someone curious enough that once they open it, they keep reading.
43% of people open an email based on the subject line alone.
And 69% of people will mark an email as spam based on the subject line without ever opening it.
So your subject line is doing a lot of heavy lifting. It has to earn the open, dodge the spam filter, and make someone curious enough to scroll.
Grab The Swipes!
Want a list of my favorite subject lines and CTAs? It’s all wrapped up here:
The Curiosity Gap: What It Is and Why It Works
The curiosity gap is the space between what your reader already knows and what they want to know. A subject line that closes that gap too early gives people no reason to open. A subject line that opens it just enough makes them feel like they have to.
The goal is to make them feel the gap before they click.
Four Subject Line Tactics That Have Been Working For My Clients
1. The One-Word Subject Line
Subject lines between two and four words get the highest open rates. But if you drop below that into one word, you can break the pattern entirely.
Examples I’ve used recently are: "Oops." "Disclosing." "Embarrassing." "Spaghetti."
People open it because they genuinely cannot figure out what you're emailing them about.
It works because it's unexpected. So if you make 1-word subject lines a habit, they’ll lose the disruption factor. Save it for when your open rates are slipping and you need a pattern interrupt.
2. Steal the Most Outrageous Line From Your Email
This is my personal favorite and the one I use most consistently. You already wrote the email. You told the story, you made the case. Now go find the sentence in that email that would make someone do a double-take and use that as your subject line.
The example I keep coming back to is a friend of mine whose husband is a professional chef. Her subject line was "The spaghetti that almost caused my divorce." Dramatic? Yes. But it worked because it was specific, a little scandalous, and it made you need to know the rest of the story.
In other words, it had a curiosity gap that got the email opened, and I read every word trying to figure out the relationship drama.
Your best subject line is probably already written. You just have to find it.
3. Keep a Swipe File
Go to your inbox right now and create a folder called Swipe File. Every time you get an email where you think "dang, that subject line got me," save it there when you're done reading.
Over time you'll start to notice patterns in what works on you. And if you are your audience (which, for a lot of us, is true), those patterns are a roadmap.
When you write a great email and have no idea what to call it, open the swipe file and look for inspo there!
4. Use Formatting to Break the Visual Pattern
Brackets are underrated. "[Action required]" creates a mild spike of anxiety that makes people click. You can also use brackets for launch announcements: "[It's here]" or "[Last chance]" stand out visually in a scrolling inbox.
One word in all caps can work too, as long as it’s just one word. Fully capped subject lines can drop your open rate and flag spam filters.
You can also add emojis or small pieces of punctuation to a subject line to draw attention. Use these sparingly as they can still flag as spam.
What to Stop Doing Immediately
1. False urgency.
Never put "RE:" in a subject line unless you're replying to a past conversation. It's technically illegal if you're not. Phrases like "ASAP," "limited time," and "act now" also tank open rates because people have been burned by fake urgency enough times that they're immune to it.
Specific urgency works. "Cart closes tonight" or "last chance at the founder's rate" are specific and true. Vague urgency reads as spam.
2. First-name personalization in the subject line.
When researching this post, I was surprised to find that studies are showing that "Samantha, open this now" is starting to flag for readers as spam. Save personalization for your pre-header instead.
3. Industry-specific spam triggers.
If you're in finance or health, words like "investment," "earn money," and even "free" can route your email straight to spam depending on context. Do some industry research before shooting off emails.
The Formula That Works Every Time
Great subject lines do one or more of these three things: create curiosity, deliver clear value, or trigger a feeling. Best case scenario, you're hitting more than one at the same time.
Think about a Father's Day email that says "Save 25% while treating Dad this year." That's value and feeling in a few words. You know what you're getting, and you're already picturing the moment.
Try It on Your Next Email
Pick one of these tactics and test it. If you have a thousand people on your list and your open rate goes up by one percent, that's ten more people reading what you wrote. Ten more people who know what you do and how to hire you.
And if you try a subject line that works? Tag me on Instagram at @nomad.copy or send me an email. I want to cheer for you!
If this episode made you realize your email copy needs a bigger overhaul than a subject line tweak, that's what Copy On Demand and my done-for-you services are for.
Helpful Resources:
Grab the Forgotten Launch Emails checklist for $1 with code PODCAST: https://nomadcopyagency.thrivecart.com/launch-emails-checklist
Grab the Clickable AF CTAs resource here: https://nomadcopyagency.thrivecart.com/clickable-af-ctas/
Connect with me:
Watch episodes with subtitles on my YouTube
See my services → sales pages, emails, websites, and more.
Get on my calendar → if you’d like me to write your sales copy for you!
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