How long does it take you to write marketing emails?
If you’re anything like me, you sweat every word. That level of care is what it takes to craft actionable newsletters and send effective cold outreach emails.
Your message is packed with value—maybe a timely offer, discount, or limited promo.
Maybe you’re launching a product, filling a webinar, or pushing traffic to a landing page. Whatever the objective, all successful email campaigns share one truth:
Subscribers have to open the email to see any of it.
Sounds obvious, but subject lines are often written in a rush at the last minute.
The subject line is the first thing people see. How important is it?
Well, research shows a huge share of people decide whether to open based on the subject line alone. On the flip side, many also flag messages as spam because of it. In short: the subject line can make or break your campaign.
To lift open rates, you need subject lines that spark interest and interaction—core ingredients of modern email marketing.
You also can’t recycle the same angle forever. Audiences catch on fast.
Use these seven proven subject line types as your go-to playbook. Keep them handy for every send.
Let’s dive in.
1. Personalized subject lines
Adding a personal touch to your subject line is still one of the most reliable ways to win the open.
Done right, personalization does more than boost opens. It improves click-through, reduces unsubscribes, and often correlates with higher revenue per email.
What can you use to personalize a subject line? Try your customers’:
- name
- postal location
- birthday
- current location
- info related to their transaction history
- content related to browsing history
- product recommendations
- social media accounts
- time since last purchase or last visit
- industry or role (for B2B)
- loyalty tier or on-site behavior (e.g., “left items in cart”)
If you’re unsure what’s appropriate, start simple: use the recipient’s first name in the subject and compare the open rate against a control.
How much of a difference can it make?
Plenty. Personalized email messages consistently outperform generic ones on opens and clicks, and personalized promos tend to see higher lift than batch-and-blast alternatives.
This works because it feels like the message was written for a person—not a list. “Hey Neil!” beats “Dear Valued Customer” every time.
Try it on your next send—and keep testing different data points to avoid fatigue.
2. Subjects that create a sense of urgency
FOMO—fear of missing out—is a powerful motivator. Social feeds have only amplified it.
Leverage urgency ethically with time-bound or quantity-bound offers. The key is clarity and a real deadline.
How can you create urgency?
Use a firm expiration date (“Ends tonight,” “48 hours left”) or a genuine scarcity cue (“Only 27 seats left”).
If someone’s on your list, they’ve likely bought before—or they’re close. Your subject line should make now the moment to act.
Compare these two:
“New weekly coupon inside!”
vs.
“25% off ends tonight.”
The second subject typically wins in A/B tests because it gives a clear reason to open now, not later.
Quantity limits can do the same thing. Here’s a classic example from GetResponse:
Urgency works best when it’s honest. Don’t fake timers or false scarcity—it erodes trust and hurts deliverability over time.
If your offer runs all month, create smaller windows inside it (“Early-bird bonus ends Sunday”) to give readers a timely reason to open today.
3. Breaking news subject lines
Relevance sells. When your subject line hooks into something timely, opens rise.
You don’t have to be a newsroom to make this work. Tie credible, real-world events to your brand or create news of your own.
For example, if you sell apparel and a major winter storm is heading for New England, target those subscribers with a subject like, “Storm incoming: stay warm—coats 20% off today.”
MailChimp analyzed billions of sends and found that time-sensitive keywords consistently lift open rates.
If you can’t credibly attach to broader news, make your own: announce a product launch, a milestone, or an upcoming event with a headline-style subject.
Great internal “news” for subject lines includes:
- a new product release
- an approaching event
- new member of your staff
- customer wins or case studies (“How ACME cut costs 37%”)
- awards, certifications, or partnerships
Write your subject like a headline—short, specific, and clear about what’s new.
4. Subject lines that tell a story
Storytelling isn’t just for sales pages. It’s a powerful open driver because humans are wired for narratives.
That’s why we binge shows and get lost in books—the promise of “what happens next” keeps attention.
Use your subject line as the teaser: set the hook, then pay it off inside the email with a clear call-to-action.
If your latest post tells a story, test the post title as your subject—especially if it includes a tension or payoff.
Numbers, contradictions, or surprising outcomes make irresistible teasers. Subjects like “I spent $5,000 to save $30,000” spark instant curiosity.
Then, deliver the story quickly in the email, and point readers to the full article, demo, or offer.
5. Stimulate curiosity with a subject line
People are naturally curious. Your subject line should invite a click without giving away the whole plot.
Tease the benefit or the reveal, then deliver the details after the open. This works for sales, announcements, and content.
Instead of “Here’s 30% off your next purchase,” try a mystery angle (“Your surprise discount is inside”). Curiosity gets the open; the body copy gets the click.
Here’s an example from Forever 21 that plays this card well:
The same idea works for events, product drops, or guest appearances. Hint at what’s coming; reveal inside.
Food brand example: rather than “Potatoes are America’s most popular vegetable,” try “America’s favorite vegetable? We’ve got the answer.”
One caution: keep curiosity honest. Clickbait subjects that don’t pay off will tank engagement and hurt deliverability.
6. Short subject lines
Whatever your angle, keep it tight. Long, cluttered subjects get truncated—and ignored.
Draft several options, trim filler words, and keep the most compelling pieces. Aim for clarity first, clever second.
How long is too long? In most inboxes, mid-length subjects strike the best balance between context and visibility. But the “right” length depends on your audience and device mix—test it.
Remember that many opens now happen on phones, where screen space is limited. What looks fine on desktop can wrap awkwardly on mobile.
Studies show a large share of email opens happen on mobile devices—optimize for small screens.
Pro tip: pair your subject with strong preview text (the preheader). Use it to extend or clarify the hook—not repeat it.
Also avoid spammy conventions (ALL CAPS, excessive punctuation!!!, bait-and-switch). Cleaner subjects get better placement and better results.
Short, specific, and scannable usually wins.
7. Subject lines with free stuff
Giving something away can be wildly effective. It doesn’t have to be your flagship product—bonuses, trials, or gifts-with-purchase work too.
Promote the free element in the subject line so people don’t miss it.
Why? Because “free” grabs attention—and email remains one of the highest-ROI channels, so the math often pencils out.
Take a look at these numbers:
Email consistently delivers outsized returns compared to other channels because sending is inexpensive and impact compounds over time.
You’re likely paying a reasonable monthly or annual fee for your software—and reaping gains in sales, traffic, and lead volume. Using that channel to promote a free add-on is smart economics.
Try explicit language like “FREE bonus today” or “Free upgrade with order”—and make sure the body copy delivers exactly what the subject promises.
Conclusion
Great emails don’t matter if people never open them. Put as much care into your subject line as you do into the message itself.
Pull from this playbook: personalize, use timely angles, tell a story, and spark curiosity—then keep it short and mobile-friendly.
When you’re running a promo, be clear about urgency and scarcity. If you’re giving something away, say it up front.
Pair every subject with strong preview text, avoid spammy formatting, and A/B test length and tone regularly.
Do this consistently and your open rates will climb—so will the downstream clicks and sales that follow.