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Silvia Woolard
27 September 2018
Reading time: 9 min

How to Write Effective Email Subject Lines

Email marketing successfully stands the test of time for over two decades. As a matter of fact, it seems like email marketing is stronger than ever, reaching a median ROI of 122% – over four times higher than other marketing formats including social media, direct mail, and paid search.

But where does it derive its power from? There are many answers to this question, but one of them definitely stands out from the crowd: almost half of all email recipients open emails based on the subject line alone.

It is by far the most important element of email marketing, so you should obviously pay more attention to it. In this post, we will show you how to write effective email subject lines.

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Features That Make a Quality Subject Line

Before we move on to the writing strategy, we should check out the features that make a good subject line. There are several things to take into consideration here:

  • Present your offer: If you have something tangible to offer to the recipient, don’t be afraid of showing it in the subject line.
  • Create a sense of urgency: Most marketers try to highlight scarcity and urgency (buy now, expires tomorrow, etc.).
  • Inspire curiosity: Intriguing subject lines make users curious and inspire them to read an email.
  • Relevance: No matter how intriguing, a subject line cannot influence recipients if it’s not relevant or timely.
  • Share news: Emails can also serve as the means of news distribution, keeping the audience informed about the latest industry developments.

15 Tips for Writing Better Subject Lines

It is time to reveal the best tactics to make your subject lines more attractive. There are dozens of valuable solutions, but we will narrow down the options and present you 15 most productive strategies. Let’s check them out:

1. Keep it brief and simple

Great subject lines are almost exclusively simple and concise, taking no more than 50 characters. It’s basically a one-line call to action that should inspire users to check out the entire message.

Content creators at Bid for Writing claim that simplicity is the key to writing a compelling headline: “Most users check email on their mobile phones, so you must consider the problem of user interface. Shorter statements allow every recipient to see the subject line, thus increasing the total open rate.”

2. Remember email segmentation

Segmented email campaigns perform much better than their non-segmented counterparts. According to the report, the average open rate is 14% higher than non-segmented campaigns. In such circumstances, you need to divide subscribers into logical units to maximize the open rate potential.

Form groups of recipients based on their locations, device types, niches, interests, or any other feature relevant to your business. That way, you will be able to design more appealing headlines and improve the credibility of email campaigns.

3. Make them feel special

Everybody loves to feel special and unique. Your email subscribers are in no way different, so you might exploit this trait to improve the effectiveness of your campaigns. Here are a few subject line ideas to help you find your own versions:

  • For your eyes only!
  • My gift to you!
  • Is this you?
  • A free sample for you!

4. Keep it personal

Personalization is very important if you want to maintain quality customer relations in the long run. If you know a subscriber’s name or location, don’t be afraid of writing tailored emails that reveal your personal appreciation.

However, don’t do it too frequently because it may seem weird or even creepy. It’s alright to address subscribers by names from time to time, but it’s not recommended it to act as if you know everything about them. Keep it personal, but stylish.

5. Avoid a ‘no-reply’ sender name

The whole purpose of email marketing is to inspire people to engage and take action based on the content. But if you disseminate messages from a ‘no-reply’ sender address, it may ruin your subject line efforts. It’s almost as if you are saying: Don’t do anything about this email, just neglect it. Therefore, avoid this email address solution to put a greater emphasis on the subject line.

6. Use a familiar sender address

Speaking of email addresses, we should mention that sender names containing real human names make the biggest impression on recipients. Adding your name to the address is the easiest way to keep the communication more personal, thus inviting users to spend more time exploring the content – starting with subject lines.

A study reveals that personalized email messages improve click-through rates by an average of 14% and conversions by 10%. Don’t let it slip away from you just because you are using boring company signatures instead of your own name.

7. Add emojis

A lot of companies use emojis these days to make their subject lines more visually appealing. Although you don’t want to exaggerate with this practice, emojis are definitely a great tactic to support your headline statement. Some examples include:

  • Your immaculate product launch for $20 (followed by the rocket emoji)
  • Last chance to use the 10% discount (followed by the alarm clock emoji)
  • The Ultimate Audience Targeting Guide (followed by a dartboard emoji)

8. Use numbers

People just love numbers. Why? It’s because numbers add to the credibility of your subject line. That way, the average recipient will really believe you are offering tangible and measurable benefits. Numbers also sound mind-boggling, so everyone wants to see what’s hiding behind them.

At the same time, digital content that relies on numbers promises quick fixes and ensures easier scanning. For instance, number-based headlines sound like this:

  • How to make 10,000 subscribers in 3 weeks
  • 10 ways to improve a landing page
  • Get your eBook with the 70% discount

9. Ask a question

When you ask a question in the subject line instead of making a statement, you are essentially inviting recipients to interact with you. It’s a conversational approach that immediately reveals your intention to explain something. The options are almost countless, but we will give you a little hint:

  • Spending a holiday in Paris this summer?
  • Hiring a freelance web designer? Use this guide!
  • Is this really you?

10. Don’t use all caps

Some marketers think that capital letters will help them to grab the recipients’ attention, but they are making a big mistake. The same goes for exclamation marks. What makes these details so disturbing? The answer is rather simple: people don’t enjoy being yelled at, so don’t do it ever again.

11. Use humor when possible

We all like to hear a nice joke from time to time, which makes humor a credible subject line creation strategy. Don’t do it too frequently (unless you are promoting a comedy website), but don’t run away from it either if you spot a good opportunity. But you better make it really soft and easy, something like this – I love my customer service job. It’s the work I hate.

12. Tell what’s inside

A subject line doesn’t always have to be funny, intriguing, or provocative. On the contrary, sometimes the most productive tactic is to simply tell what’s hiding inside the message.

For instance, a subscriber might expect to receive the new eBook or case study. In this case, you can just reveal it in the headline. This is more than enough to inspire a recipient to open your email and check out the content.

13. Mind the timing

If your message is time-sensitive, you should pay attention to the sending schedule. For instance, you could send something like “Top 10 Cocktail Bars to Visit Tonight.” However, make sure to send it on Friday or Saturday morning because that’s when most people are making plans for the party night. But if you send it on Monday morning, your email will probably end up in a trashcan.

14. Don’t make false promises

You should never write subject lines that promise more than you can deliver. Avoid sensational headlines and unrealistic statements. First of all, most recipients won’t believe you. And secondly, you will lose professional credibility, which will eventually lead to losing subscribers. Keep your promises and don’t bite off more than you can chew – that’s the formula for the long-term email marketing success.

15. Make sure to test different options

Now that you’ve seen various email subject line tactics, you only need to know one more thing, A/B testingTest different subject lines and see how they resonate with the target audience. For example, you might notice that question-based headlines perform much better than emojis. That way, you can eliminate pain points and promote content that increases open rates.


Email campaigns represent the most profitable marketing strategy, ensuring much higher ROI than social media, paid advertising, and other channels of promotion. But there is one element – a subject line – that makes email messages particularly attractive.

This article explained to you how to write effective email subject lines. Did you already use some of these tricks? Do you have other interesting suggestions to share with our readers? Feel free to let us know in comments – we will be glad to learn more subject line ideas!

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Silvia Woolard

Silvia Woolard is a freelance writer and novice entrepreneur from Phoenix, AZ. In her free time, she writes and works in a field of popular psychology and marketing. Read Silvia at Twitter (@silvia.woolard).

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