How To Write Killer Subject Lines

Last updated


Daniel Wade


July 28, 2022

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For some of your customers, a subject line is all they’ll ever read. Finding the right words to pique their interest then, is not only important, but vital to your business’ success.

But how do you know what to include in your subject line? The key is to arouse curiosity, drive some sort of urgency, or otherwise create an irresistible urge to keep reading. How you do that is up to you, but in this article, we’ll go through some of the more popular ones used by successful companies around the world.

Most people write a subject line as an afterthought to the actual content of the email itself, but what we encourage is to write with the subject line in mind first. Indeed, having a sharp, clear, and concise summary of your e-mail’s content will not only help drive up your open rate, but will also make your content stronger overall.

Results are ultimately what matters, though. That’s why we’ve selected only the highest-performing techniques that are employed by businesses and entrepreneurs everywhere to increase their own conversions. If it can work for them, it can work for you too!


Table of contents

Examples of High-Performing Subject Lines

When most people sit down to craft an email to their audience, they usually put a lot of thought into the content itself. They wonder what kind of information should be in the intro paragraph, how many images (if any) to supply, as well as how to drive the reader to an eventual action (buy, read, forward, etc).

What we don’t spend nearly as much time thinking about is our subject lines, even though that short little sentence is the gateway to the rest of your email. If it’s not catchy enough, no one will open the email, and all that other work will go to waste.

If most marketers were honest, they would admit that crafting the perfect subject line is usually the hardest part. With hundreds or even thousands of words, we can explain everything in its entirety. Condensing that down to 50 characters or less takes a lot of thought.

Below are some examples of awesome subject lines that you can put in your swipe file for when you need them, along with a brief explanation as to why each one of them works.

“Important Weather Advisory”

Weather-related alerts have a way of capturing our attention, whether that’s about a hurricane, tornado, or even extreme heat. It means that you need to take action now, regardless of whatever you happen to be in the middle of at the time.

This email wasn’t sent out by a weather company, however, but by RCN, a New Jersey-based internet, television and phone provider. What’s more is they weren’t even warning potential customers about an impending weather situation; what they were doing is alerting them about the potential of outages, and providing solutions that will keep these services intact in a time of need.

“What Can You Afford?”

Questions work really, really well when it comes to subject lines. They force the reader to respond in some way, even if that action ultimately never leads to an opened email.

This email though, sent out by the online real estate marketplace ZIllow, was a massive success. By creating a question in their subject line, Zillow was able to make the e-mail seem more personal without ever actually mentioning the reader’s name. It also made them want to open up to see what types of homes they could afford, which resulted in a click-through rate that went through the roof.

“DO NOT Commit These Instagram Atrocities”

Knowing your audience is everything, and in this case, Thrillist knew that their readers were heavy social media users. For that reason, they made sure to include a couple components in this email blast: fear and entertainment.

We’ve all seen social media posts that are cringeworthy, and Thrillist played into this fear by showing their readers examples of what not to post on Instagram, in addition to a few tips on how to avoid it. Even if readers aren’t on Instagram themselves, they also would have opened up the email to see what type of silly posts people had made.

“9 Disgusting Facts About Thanksgiving”

Holidays are usually seen as events of love, family, and food. That’s why Eat This, Not That decided to send out this email to their readers destroying every popular perception that we sometimes have with one of the most well-loved holidays: Thanksgiving.

The goal here was not to sell the reader anything; instead, what ETNT wanted to do was simply generate useful content and drive traffic to their website. This is part of the “service” mentality that is so important to digital marketing (and conversely, so underused). If you try to sell everything all the time, people will stop opening your emails. Providing them with content-heavy emails though is a surefire way to make that open rate pop.

“They Did WHAT With a Pair of Crocs?”

In a highly competitive industry like footwear, Crocs have managed to carve out their own little niche of devotees. They wear them everywhere — even with suits! — so it makes sense that they would have an email with just information about how you can use your Crocs.

But rather than just say “Here are five ways Crocs are used,” which is boring, they rolled out this subject line instead. Some people undoubtedly opened this out of curiosity, but I’m willing to bet that at least a few people got ideas for their own personal use — and ordered some pairs to make it possible.

Once again, entertainment and content go hand in hand to drive up sales.

Tips on Writing Killer Subject Lines

When it all comes down to it, writing killer subject lines is all about creating a sense of curiosity in your reader. Social media experts call this phenomenon “stopping the scroll,” and that should be your goal as well. You want people to “stop scrolling” as they check their email and open your message up because they simply can’t resist knowing what’s inside.

But how do you do that? Here are a few tips gleaned from industry experts, many of which were incorporated in the above examples.

Tell a Story

Who doesn’t love a good story? Even if they have no interest in actually buying something, most people will open up an email if they think there’s a chance that they’ll be entertained or informed. Writing a subject line that starts with “Why I Always Buy Travel Insurance” may not sound like the beginning of the next great American classic, but it does tease an interesting story on the inside of the email. All they need to do is click “open.”

Of all the industries out there writing story-based subject lines, adventure and lifestyle companies do it best. Brands like REI and Patagonia usually have great examples of these types of subject lines.

Drop a Name

No, I don’t mean someone else’s name, I mean the recipient’s name. Nearly every major email marketing service today allows you to insert customization options right into the subject line, such as a person’s first name. There’s something about reading your own name in print that makes you pay attention, even if it is on a generic marketing email.

Truthfully, this method can be overused, so it’s better to pair it with something attention grabbing, like, “Hey Mike, did you forget something?” (for an abandoned cart email). If you really want to turn up the heat, try using an emoji too, even if it replaces a word or too. Instead of saying that you have “hot” deals, for instance, use the fire emoji. It means more and it stands out on the page.

Keep it Simple

Regardless of what you think about him, Barack Obama is a master marketer — or, at the very least, has a master marketing team behind him. His 2008 and 2012 campaign emails were so simplistic and downright boring so as to be completely irrelevant if they were sent by someone else.

And yet, there was something stunningly intriguing about them. One subject line literally had only the word “Hey” in it, as if the President of the United States was writing you a personalized note. It’s simple but uber powerful, especially when every other company around you is writing subject lines that are at max capacity.

Tell Them the Offer

When all else fails, just cut to the chase. If you’ve got a coupon for 20% off on the inside, let them know. If there’s an ongoing BOGO deal that you want your customers to take advantage of, say it in the subject line. These types of emails work great for follow-up orders or abandoned cart emails.

Be very careful of bait and switch tactics though. Whatever you promise in the subject line needs to be included in the email, or not only will they unsubscribe, but they may also mark you as spam.

How To Write Killer Subject Lines


Daniel Wade

Daniel Wade

After working for multiple digital advertising agencies and managing hundreds of client accounts and spending millions of dollars via Google Ads, Facebook Ads, Native Ads and Direct Media Buying, I took things out on my own and started SparrowBoost. Now, my tight-knit team and I continue to get smarter and more efficient at running our own campaigns and we share our knowledge with you.

Learn more about SparrowBoost