Email Subject Lines: 9 Copywriting Techniques to Boost Open Rates
By Cara Berkeley
Email is still one of the most effective channels to engage, convert, and retain potential customers, but it's getting harder to stand out in people's inboxes. By 2025, the number of emails sent and received globally each day is estimated to reach 376 billion—an increase of 28% compared to 2019, according to Statista.
For this reason, writing engaging email subject lines has become more important than ever. You only have one chance to stand out and to grab your reader’s interest enough to open your email.
How to write the perfect email subject line
Here are nine copywriting techniques to create more attention-grabbing subject lines and give a boost to your email open rates.
1. Try using no more than five words
A Yesware study found that open rates were at their highest with email subject lines between one and five words. And, according to a Marketo study, subject lines with around 41 characters or seven words achieved more engagement overall.
It is a common pitfall for businesses to cram too much information in any one message. But in marketing often less really is more. Short and sweet email subject lines like “Products celebs are wearing” or “Deals you can’t miss” will get the point across and gain interest.
If the subject line needs to be longer than five words, put the most compelling information at the beginning. Your email subject line should just be a short and simple hook to bring the reader in.
2. Use numbers in your email subject line
Numbers help your subject lines stand out and also add credibility to your message. Yesware found that email subject lines that included a number had higher than average open and reply rates.
Include a statistic from a survey, a time-saving figure, the discount percentage figure, or the number of steps in your how-to guide. Break style guide rules by writing numbers less than 10 as numerals.
Examples of data-driven subject lines:
- “40% off today only”
- “15 ways to save on energy”
Infographics, which generally contain data and statistics, have become an increasingly popular piece of content. Use an infographic in the body copy of your email and tease it out with some of the data in your subject line.
3. Add intrigue or make an honest promise
To create more compelling subject lines, make sure they're intriguing or feature a promise. Consider using questions to build interest, or promise to reveal how readers can achieve something. For example:
- “David, is your home priced to sell quickly?”
- “Jane, here's how to boost your home's value.”
As with any marketing, make sure you are aware of your customers’ pain points and leverage them in your email subject line. A promised solution or answer for their issues will be hard to resist.
Make sure the actual email copy stays true to the subject line. Early on in the email body, reveal the answer to your question or uncover what you promised to reveal. Otherwise, you risk creating a negative response in your reader and maybe even a dreaded unsubscribe.
4. Combine personalization with conversational language
Various studies have reported a link between personalization and higher engagement levels. Personalized subject lines can even boost open rates by as much as 50%. While this is a well-known phenomenon, many businesses still underestimate the power of addressing the reader by name.
To make your email subject lines sound even more personal, keep the language informal and write like you're talking to a friend. “Linda, we don’t want you to miss out” or “This will look good on you, Linda” will increase your email open rates.
5. Sharpen up your unique voice
In a crowded inbox, you need to use language that sets you apart from other businesses. A distinct brand voice that highlights your personality is something that your competitors can't replicate.
Use language that is unique to you and complements your personality. Choose unconventional words to make your subject lines more memorable. Humor is one tool you can use to increase your inbox uniqueness.
Activewear retailer Fabletics combined brand personality with insight into what matters to their customers in this subject line: “Your butt will look great in these workout pants.” You can see how that one choice of word also makes this email stand out!
And Groupon knows how to use humor, as in this subject line: “Deals That Make Us Proud (Unlike Our Nephew, Steve).”
Having a brand personality and a unique copywriting voice will influence your customers to read more.
More articles from AllBusiness.com:
- 6 Ways to Leverage Email to Increase Sales
- 6 Email Productivity Tips Every Professional Should Know
- 4 Little Email Marketing No-Nos That Could Land You in Big Trouble
- 6 Email Marketing Tips to Help Your Business Grow
6. Use title case
There's no magic formula that will guarantee higher open rates, but one study showed that subject lines in title case are slightly more effective. When the major words of the subject line are capitalized, it seems to add authority to the message.
Try split testing two identical subject lines—one in title case and the other in sentence case. Then measure the open rates for each version. Just one word as in these examples can make your email stand out in their inbox:
- “We miss YOU”
- “FLASH Sale today only”
7. Experiment with emojis
Using an emoji in the subject line can help your message stand out in an inbox. According to Experian, including an emoji can increase open rates by around 45%.
However, emojis aren't always a good idea. For example, if you're a B2B business or a more formal business such as a law office or accounting firm, emojis might seem inappropriate.
Experiment by split testing two versions of the same subject line—one with an emoji and one without. Just make sure you test your subject lines with emojis on different devices and platforms; some emojis display incorrectly and it could look like a mistake.
8. Use second-person pronouns
Second-person pronouns such as “you,” “your,” “yours,” and “yourself” can add instant appeal to subject lines. Put simply, they make the reader feel more emotionally connected to your business and the message.
“You are not going to want to miss this” and “These jeans would look good on you” make the customer feel like you know them.
Write about the reader, not your business. Emphasize how the reader will benefit from opening your email. If you don't know their name, use a second-person pronoun to make the message sound more personal.
9. Use the FOMO technique periodically
Using FOMO (fear of missing out) in marketing is nothing new.
For example: “Peter, your 20 percent discount expires at midnight.” However, it can backfire. If you promote a limited-time offer one week, only to offer a similar promotion the following week, it can foster mistrust and damage your reputation.
Loss-aversion strategies might be a great tactic for boosting engagement in the short term, but it can get annoying. If you do it too often, it can seem inauthentic and repel potential customers. Use it periodically to boost email open rates, but use it carefully and honestly.
A well-crafted email subject line will boost your open rates
For any business growing an email list of subscribers is a cornerstone marketing activity. And as email marketing continues to grow more competitive, writing effective subject lines is one of the most important skills for any email marketer.
While there's no silver bullet for creating a perfect email subject line, these copywriting techniques can help your emails stand out.
For best results, use a combination of two or three of the strategies outlined here. And don't be afraid to experiment. A/B test different versions, measure the results, and focus on what works for your unique business and audience.
RELATED: How to Write a Cold Email That Gets Results
About the Author
Post by:Cara Berkeley
Cara Berkeley is a blogger, investment property owner, and full-time marketing executive. She's learned that thinking outside the box can make all the difference and shares tips and tricks on smart money management and investing on her blog at www.pennypolly.com
Company: Penny Polly
Website:
www.pennypolly.com
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