The latest research from our sister brand Campaign Monitor shows that only around 15% to 25% of emails ever get opened. If you have a small to medium-sized business, that means you can expect subscribers to ignore roughly four out of every five emails you send.

But don’t get disheartened! Writing captivating email subject lines is an art. And, in this post, we’re going to teach you how to write subject lines your subscribers can’t resist.

But First: We’re Throwing You a C.U.R.V.E.

All good subject lines have one or more of these five elements:

Curiosity: Pique subscribers’ interest by telling them something they don’t know. The more shocking or surprising, the better. Or, ask questions—just not the yes or no kind.

Urgency: Your email subject line should make your readers stop scrolling and open their email RIGHT NOW instead of saving it for later. If they’re not worried about what they’re missing out on, you’ve still got work to do.

Relevance: A gripping subject line speaks directly to your subscribers’s needs, wants, and desires. It should feel personal, even if you didn’t personalize it.  

Value: Explain—or hint at—how your email will change their lives, even if it’s just saving a bonkers amount on a popular product.

Emotion: How do you want your email to make your subscribers feel: Excited? Anxious? Happy? Comforted? Whatever emotion you want to evoke, just make sure you do it right away—don’t wait for them to open your message or miss the chance entirely.

Of course, you won’t be able to squeeze in all these things into your email subject line every time. Nor should you try. Which elements you use will depend on what your email message is supposed to accomplish. 

Also, you should know which subject line templates drive your subscribers to click and convert most often (if not, that’s a good place to start your A/B testing program).

Which brings us to…

7 Email Subject Lines People Can’t Resist

Now, let’s look at seven tried-and-true subject line templates that incorporate the C.U.R.V.E. principles we just shared:

1. FOMO

No one likes to feel like they’re missing out, especially on a great deal. An easy, effective way to create urgency with nothing but your email subject lines is to add a deadline before an event ends or a product sells out to create the impression of scarcity. 

Example: “Last chance! Just 5 spaces left on our exclusive training webinar.”

2. Self-Improvement

Ah, a dependable classic. Promising people they can be a better version of themselves isn’t new, but boy does it work. Put another way, it answers the customer’s most pressing internal question: “What’s in it for me?”

Example: “Get six-pack abs in just 10 weeks”

3. The If-Then Statement

If you know your target audience well enough, then you’ll have a good idea of which characteristics they share. Mention a situation that applies to most, if not all, of the people on your list starting with your subject line. Then, link this to the solution you’re emailing them about. That makes any reader think, “Oh, wait, that applies to me!” And just like that, your email is scarily relevant.

Example: “Struggling with staff shortages? You need THIS tool.”

4. Freebies

No, putting “free” in your subject lines will not drive your email to the spam folder. Everybody likes to get something for nothing. So, give your subscribers the impression that something real and tangible is waiting for them. This approach is always a winner because it’s a great way to cut through all of the competing noise in your customers’ inboxes—especially if you personalize it too.

Example:. “Hi Ben! This month’s free marketing tutorial is now ready for your viewing pleasure.”

5. Cliffhangers

Humans are curious creatures. Create a little mystery or suspense and we can’t help but peek inside. Don’t believe me? Scroll to the bottom of this page to find out why.

Example: “Pssst! Bet you don’t know this profit-boosting trick”

6. Keeping It Casual

Being informal with subject lines is an increasingly popular method, with good reason. The idea is to mimic the way real people write subject lines to each other, be they friends or colleagues, to eliminate the sales and marketing speak that scares most subscribers away from your emails.

Example: “Are you free for a 10-minute chat tomorrow?”

7. Controversy

Okay, so you need to exercise this subject line tactic with extreme caution. Making an outlandish claim or questioning a popular belief is a great way to get clicks. Just make sure you aren’t overdoing it, or you’ll lose people’s trust! And they won’t click through to your website, which is what your email is supposed to do in the first place.

Example:  “Are you wasting money on Facebook advertising? Here’s why you need to stop, today.“

Two More Tips to Drive Even More Email Engagement

1. Front-Load your main point.

Most inboxes will cut off the subject line somewhere between 60 and 80 characters. Meaning that—if you’re offering a discount or have something specific you want your subscribers to do—you should put that info at the start of your subject line, not at the end, to guarantee it’s seen. 

You might also have heard that short subject lines are better. That’s something else your A/B testing can help you prove or reject. An informal rule of thumb is that shorter subject lines drive more opens, but longer lines drive more clicks. And considering all of Apple’s recent changes, the door has never been open wider for new subject line innovation.

2. Use action-oriented verbs. 

Use strong verbs that tell subscribers exactly what you want them to do. Some good examples to start testing: “discover,” “reveal,” and “learn.” 

With email open rates becoming less reliable as a measure of customer engagement by the day, your subject lines need to amp up their click, conversion, and engagement-driving capabilities. This approach helps you measure what your customers are interested in, even if the click itself doesn’t lead to a conversion. 

Along with this new focus on engagement-focused success metrics, pay attention to what people are clicking on in your emails. Do the clicks correspond with your subject line, or are people clicking on other things like secondary offers or in-email navigation? Knowing the answers to questions like these future-proof your campaigns and make your next send even more effective.

One last word of advice: Test your subject lines before you depart from any standard formats. What works for one brand may not fly with your audience, so don’t be afraid to try and do new things. If you’re looking for even more inspiration, download The Smart Marketer’s Guide to 2021 Holiday Success now!