Copywriting
How to write a subject line that earns the open without tricking anyone
A subject line earns the open by telling the reader plainly what the email is about and giving them a real reason to want it. Then the email pays that off in its first few lines. Name the specific thing, add curiosity the email actually resolves, write it the way you’d say it out loud, and only use news and deadlines that are real.
Two subject lines I’ve actually sent: “Why old POST IDs might be messing up your ads …” and “Here’s the crazy reason I don’t use any tracking tools for ads, and no one has ever been able to give me a great counter to it …”
Neither one is clever. Neither one is a trick either. Each tells you exactly what the email is about, gives you a reason to care, and the email delivers on it straight away.
A trick is any subject line that gets the open by promising something the email doesn’t deliver, or by pretending to be something it isn’t. The fake reply, the fake deadline, the alarm bell over a regular newsletter. It might work once. Then the reader learns what your name in their inbox means.
I’m convinced people can feel when something is inauthentic and not true. They feel it in their bones. So here’s how I write them instead.
Step one: know what the email is about first
Most bad subject lines are a symptom. The writer didn’t know what the email was for, so the subject line had nothing real to point at and turned into a teaser for nothing.
I try to give every email one job: get a click or get a reply. Before I write the subject, I want to be able to say in one plain sentence what the reader gets from opening it. If I can’t, the problem is the email, and no subject line fixes that.
This is the same thing I tell people about ads. When the copy won’t come, it’s usually because the idea underneath it isn’t clear yet.
Step two: name the specific thing
Look at the Post IDs subject line again. It names a specific thing (Post IDs) and a consequence the reader cares about (messing up your ads). Anyone running ads who has ever wondered why a good ad went bad knows immediately whether that email is for them.
That’s the pattern I come back to: the specific mechanism, plus a gap the reader wants closed. A vague subject line like “Quick tip for your ads” makes the reader do the work of guessing. A specific one does the work for them.
Specific also means their words, not yours. One subject line in a launch sequence of mine was just the reader’s objection in quotes: “I’ve been burned by courses like this before.” If that’s the exact sentence in their head, you don’t need to be clever. You need to be accurate.
And write it how you’d say it. Plain words, no caps-lock, no emoji. Mine often trail off with an ellipsis because that’s how I talk.
Step three: add curiosity the email actually resolves
Curiosity isn’t the problem. Curiosity with nothing behind it is.
During one launch I sent an email with the subject “Something I left off the order page on purpose.” The first line of the email told them what it was, a bonus that wasn’t listed anywhere on the order page, and then explained why I’d kept it off. The curiosity was real, and it got resolved in the first few sentences.
The tracking tools email does the same. The very first line after the subject is the reason: Meta sequences your ads. The rest of the email is the argument for it.
This matters for the same reason it matters in ads. I optimize ads for intent over curiosity, because curiosity pulls in people who want to know what something is about, not people who want the thing. Email works the same way. It’s why I treat subject lines the way I treat the first two lines of a cold ad: get the right person to open, not everyone.
Step four: only use real news and real deadlines
Deadline subject lines are where most of the tricks live. “Last chance”, “Closing tonight”, “Final hours” on something that isn’t closing.
I really don’t like doing the whole “limited-time” thing on an offer that stays open. It feels inauthentic to me, especially for something people can watch or buy on demand. When a promotion on an evergreen offer ends, I’d rather just stop promoting it than write a cart-close email for a cart that never closes.
When the deadline is real, say it plainly. “Cart closes tonight” is a fine subject line when the cart closes tonight. And when the news is real, like a price actually going up, you don’t need to dress it up at all. That kind of plain, slightly uncomfortable honesty tends to be the email that sells anyway.
How to tell a subject line overpromised
The way I read email numbers is simple. Opens tell you about the subject line. Clicks tell you about the copy.
So if a subject line gets a big open rate and the clicks are flat, it’s worth asking whether the subject promised something the email didn’t deliver, or pulled in people who were only curious. A high open rate is not a win on its own.
There’s one honest exception to all of this. When the reader is already expecting the email, plain is the right call. “Your workshop starts in 1 hour” doesn’t need a mechanism or a gap. They signed up. Tell them what’s happening.
What to do this week
Pull up your last ten sent emails. For each one, read the subject line and then only the first three lines of the email, nothing else. If the email hasn’t started paying off what the subject promised by line three, rewrite either the subject or the opening so they match. Then look at any deadline in those subject lines and ask whether it was real.
Is a curiosity subject line the same as clickbait?
No. Curiosity is fine when the email resolves it quickly and the reader gets what the subject implied. It turns into clickbait when the email doesn’t deliver, or when the curiosity has nothing to do with what you actually want the reader to do. Pay it off in the first few lines.
Should I put a deadline in my email subject line?
Only if the deadline is real. If the cart genuinely closes or the price genuinely goes up, say it plainly in the subject. If the offer stays open after the promotion, stop promoting it instead of writing a last-chance email. A fake deadline also makes your next real one harder to believe.
Why are my open rates high but nobody clicks?
Opens mostly reflect the subject line and clicks mostly reflect the copy. High opens with low clicks often means the subject line promised something the email didn’t deliver, or attracted readers who were only curious. Read the subject and the first three lines together and check that they match.
P.S. The trick most people pull without noticing is a subject line written for the email they meant to write, sitting on top of the one they actually wrote. Read the two together before you hit send.
