7 Subject Line Formulas So Good, Your Open Rates Won’t Know What Hit Them

Let’s face it—email open rates aren’t what they used to be.

Inboxes are crowded. Your audience is scrolling fast. And you’ve got just one shot to grab attention: your subject line.

If you’ve been seeing nothing but tumbleweeds in your email metrics, don’t panic. Here are 7 subject line formulas that are proven to stop the scroll, spark curiosity, and get your emails opened.

1. The Curiosity Hook

"You won’t believe what happened to our sales after this one change"

• Why it works: It taps into your reader’s FOMO and natural curiosity.

• Use it when: You’re teasing results, stories, or announcements.

2. The [Number] + [Pain Point] Combo

"3 Reasons Your Emails Aren’t Getting Opened (And How to Fix Them)"

• Why it works: Numbers give structure and urgency, while the pain point resonates.

• Use it when: Sharing educational content, blog posts, or tips.

3. The “Quick Win” Format

"Boost Your Open Rates in 10 Minutes or Less"

• Why it works: People love fast results with minimal effort.

• Use it when: Offering hacks, tools, or new strategies.

4. The Personalized Question

"Still struggling with low open rates, [First Name]?"

• Why it works: It feels personal and conversational, like a DM from a friend.

• Use it when: Re-engaging cold subscribers or starting a nurture sequence.

5. The Contrarian Angle

"Why ‘Best Practices’ Are Killing Your Open Rates"

• Why it works: It challenges conventional wisdom and sparks intrigue.

• Use it when: You have a strong opinion or insight to share.

6. The Mystery Offer

"A little surprise (just for you)"

• Why it works: Surprises trigger dopamine and open rates.

• Use it when: Running promos, launching freebies, or thanking subscribers.

7. The “You vs. Them” Challenge

"Most brands get this wrong. Do you?"

• Why it works: It makes the reader reflect and question themselves (in a good way).

• Use it when: Sharing insights, mistakes, or thought leadership content.

Tip:

Test different subject line formulas in your next few campaigns. Even a slight increase in open rates can lead to more clicks, conversions, and revenue.

Don’t forget your preview text—it’s the sidekick to your subject line, and it matters just as much.

A good copy doesn't shout. It speaks to real people.
And your subject line? It’s the first word in that conversation.

So, which one will you try next?