Subject Line Secrets: How to Get More Opens & Clicks on Your Emails
A deep dive into high-performing subject line formulas, with examples from Gary Halbert, Dan Kennedy, and other copywriting greats.
Why Subject Lines Make or Break Your Emails
Your subject line is the gatekeeper.
No matter how brilliant your copy is inside the email, if the subject line flops—nobody’s reading it.
According to OptinMonster, 47% of people open emails based on the subject line alone. On the flip side, 69% report emails as spam purely because of the subject line.
That’s a lot of pressure for one line of copy.
The good news? There are proven formulas and principles—written and battle-tested by the best in the business—that still work today.
Let’s break them down.
What the Greats Knew (and You Should, Too)
Gary Halbert once said,
“The written word is the strongest source of power in the entire universe.”
But in his world, the envelope had to do the heavy lifting before anyone even got to the message.
Today, the subject line is your envelope—and most people treat it like an afterthought.
Dan Kennedy, master of direct response, taught that attention is the most expensive commodity online.
Your subject line has one job: get the email opened. It’s not about being clever. It’s about being clear, urgent, or curiosity-provoking.
(If you want to make a powerful first impression once they open the email, here’s how to write a welcome email that turns subscribers into clients.)
4 Proven Subject Line Formulas (With High-Converting Examples)
1. Curiosity + Specificity = Clicks
This is one of Gary Halbert’s favourite techniques. Get them intrigued—but don’t give the punchline away.
Examples:
“The 3-word phrase that doubled my client’s sales”
“What I learned from a $10K mistake (so you don’t have to)”
“Why your list isn’t buying—and how to fix it”
Why it works:
Curiosity pulls them in. Specificity builds credibility. It feels like they’re getting insider info—and they are.
2. The Direct Benefit Headline
This is pure Dan Kennedy. No fluff. Just tell them exactly what they’ll get if they open the email.
Examples:
“How to write a sales page that sells (without sounding desperate)”
“Get 3 new coaching clients this week using this 5-email sequence”
“The exact subject line that got a 78% open rate”
Why it works:
This is copy stripped down to the bare essentials. Clear beats clever, every time.
3. The Fascination-Driven Bullet
Ben Settle turned this style into an art form. Think of it like a teaser trailer in subject line form.
Examples:
“Why your welcome email is secretly killing your conversions”
“The deadliest word in your sales copy (and what to use instead)”
“What the top 1% of coaches put in their PS line”
Why it works:
These take inspiration from the classic “fascination bullets” used in long-form sales letters. They’re addictive because they create open loops your brain wants to close.
4. The Contrarian Hook
People love a fresh take—especially when it goes against conventional wisdom.
Examples:
“Forget storytelling. Try this instead.”
“Unpopular opinion: your email list doesn’t need to be big”
“I don’t care about open rates—and here’s why”
Why it works:
Contrarian headlines trigger curiosity and challenge the reader. If everyone’s zigging, you zag.
5 Rules for Writing Subject Lines That Actually Work
Test short vs. long. Some niches prefer snappy; others want a bit more story.
Use the first-person voice sparingly. “Here’s what I learned” often feels more human than “This is what coaches need.”
Avoid spam triggers. “Free,” “Cash,” “Buy now,” or overusing ALL CAPS can send your email to the promo tab or worse.
Front-load the value. Put the most compelling word or phrase at the start.
Don’t be afraid to write 10+ variations. The best subject lines are rarely your first draft.
(A high-performing subject line is only half the story—here’s how to write sales emails that convert without sounding pushy.)
Ben Settle-Style Bullet Recap
Here’s a quick-fire list to test or swipe next time you’re stuck:
The 2-word subject line that revived a dead list
Why long subject lines still work (if you do this one thing)
How a lazy email got more sales than my entire funnel
The most persuasive word you’re not using in your subject lines
One email. One tweak. 237% more opens.
Need Subject Lines That Actually Sell?
If you’re sending email after email and still hearing crickets, you don’t have an email problem—you have a messaging problem.
That’s where I come in.
I help personal brands and coaches write direct response copy that converts—without sounding pushy, fake, or generic.
👉 Ready for welcome sequences, daily emails, or sales copy that actually does its job?
Click here, fill in the form, and we can book in a quick call. to
Hey there, Rebecca here.
My mission is to write copy that feels unmistakably you—capturing your voice, sharing your stories, and engaging your audience in a way that drives real impact.
