Writing the best email marketing subject line for your next campaign

Writing the best email marketing subject line

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How to Write The Best Email Marketing Subject Line

Writing the beset email marketing subject line

Do you give your email subject lines the attention they need?

Writing the best email marketing subject line for your email campaign is all about making the right first impression.

Subject lines are judged on their ability to drive opens and get emails noticed in the inbox.

But they are infuriatingly difficult to write.

A poorly written subject line risks alienating the recipient before the email has the chance to perform.

In this blog post, we will discuss the features of the best email subject lines and how you can use this insight to optimise your own campaigns.

Don’t worry, we will offer you some simple steps to help write them along the way.

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Your Email In The Inbox

Once your email reaches the recipient’s inbox, you have three chances to get their attention:

  • The Subject Line
  • The Preview Text
  • The From Name

In a previous blog post we discussed how the email preview text is important, especially when viewing your inbox on mobile devices.  However, the preview text is rendered useless if it is not supported by a strong subject line.

The subject line is the foundation of your email campaign and without solid foundations, you have nothing.

Notice how you judge someone within 17 seconds of meeting them?  You have even less time to make the right first impression with an email.

Get these three elements wrong and you might never get your recipient’s trust back again.  How bad would that be?

Creating a Successful Email Subject Line

First and foremost, you need to grab your contacts’ attention.

The success of a subject line is judged on its ability to convince the user to open.


Once you have their attention, you can then start to sell the benefits of doing what you want them to do with the email content.

Without their attention, the rest of your email is a waste of time and space.

It needs to be well thought out and capable of communicating the benefits of the whole email in a few short words.

Your email subject line is no small detail.

Advice For Writing the Perfect Subject Line

We’re confused as to why subject lines are often seen as an afterthought.  Marketers spend so much of their time creating the perfect email copy and design that they forget how important the subject line really is.

Spend time crafting the perfect subject line for your campaign and you will be rewarded with a significant improvement in email open rates.

I’m sorry to say that there is no simple formula to write your next subject line, nor is there an ‘easy’ shortcut that you can take.

And, of course, the ‘Perfect Subject Line’ is elusive. There is no single best performing subject line when it comes to marketing.

It changes with each email campaign.

Each subject line that you write needs to focus on the benefits of the email it represents.

Sure, there are plenty of structures you can follow but each campaign is unique.  They deserve your full attention every time.

To write the perfect subject line, you need to:

Offer value to your recipient

For a subject line to succeed, it needs to offer value to the recipient.

How do I do that?

To deliver value in a subject line is not as hard or as mystical as it first sounds.

It just needs some thought.

By value, we mean showing the recipient how they can benefit from your email campaign.

This may be as simple as stating how many hours of their working day they can save by using your solution.  Or it could focus on what percentage ROI increase they can expect from a particular technique.  Your email content should back up this value by explaining how to make that promise a reality.

Getting this value across in the subject line is the first challenge on your way to creating a high performance email campaign.

Here’s an example of what we are talking about:

Feature Focused Subject Line:  Find out about our marketing automation package

Benefit Focused Subject Line:  Discover how Marketing Automation can improve ROI by 20%

In the feature focused subject line, the reader doesn’t have a reason to open unless they are specifically looking out for that feature.

Just think about that for a moment.

You wouldn’t be excited to see the feature focused subject line arrive in your inbox.  Most of the time, you would cast it aside as just another marketing email.

However, spin that into a benefit and the email becomes much more enticing.

Email subject lines that promote the value the email campaign offers give the recipient a clear reason to open Click To Tweet

Who doesn’t want to increase their return on investment?

The benefit focused subject line gives your recipient a reason to be excited.

Why not take a look at this short discussion from Digital Marketer for a quick overview of writing effective email subject lines:

Don’t Shout

Using capital letters in your subject lines doesn’t make your emails stand out in the inbox.  It certainly doesn’t make your emails look more enticing.

If you feel the need to capitalise your email subject line, you need to rethink the subject line itself.

When you see capital letters in email subject lines it just makes it seem like you are being shouted at, doesn't it? #copywriting #emailmarketing Click To Tweet

Let the words you use do the talking.

Furthermore, excessive use of capitals or exclamation marks in your subject line may trigger spam traps.

Avoid Spam Traps

Even before your campaign has chance to reach the inbox, your subject line impacts email deliverability.

You should make sure that your subject lines avoid known problem phrases which are sure to consign your email to the spam folder.

Avoiding spam traps is mainly a common sense issue but it can be easy to get caught out.  Spam filters are set up to identify low quality content which is likely to be irrelevant to the reader.

Some phrases to avoid include:

  • Click Here
  • This isn’t junk
  • We hate spam
  • You won’t believe your eyes, and
  • Increase Your Sales

Notice how none of these ‘spam phrases’ gives any value to the reader.

You could argue that ‘Increase your sales’ suggests that the email content would be extremely useful to a business.  However, the subject line is so generic that it fails to be effective.

Focus on one action

The best emails are created around one call to action.

The same goes for effective email subject lines.

Be clear about what you expect your recipient to do.

A subject line which gives the recipient an indication of what they are expected to do once they open it does some of the legwork that would be expected of the email itself.

Trying to solve too many problems with your email subject line leads to a cluttered and confused message.

Play on Your Recipient’s Emotions

One of the best ways to engage your recipients is through their heart strings.  A high proportion of decisions are made using emotional cues and it is important to reflect this when writing your subject lines.

In the short amount of time you have to catch your recipient’s attention, reminding them of how they are hurting, suffering, or how much better they could feel is a powerful tactic.

In a recent copywriting course, our marketing team learned just how much they could use emotional triggers in their email copy.

90% of purchase decisions are made emotionally

Sure, we knew the benefits of playing on the reader’s emotions already but it is startling just how much of the decision making process is swayed by emotions.

Subject lines such as ‘Want to get rid of the holiday blues?’ carefully leverage emotions to drive increased open rates.

When using this type of subject line it is important to focus on how you can positively impact the negative emotion that your recipients are feeling.

The key to make emotionally driven subject lines work for you is to speak to your recipient’s emotions using their language.  Mirroring their use of language demonstrates that you are in tune with your audience.

Use Your Data

Remember how we always talk about using marketing data?

email marketing subject line open rates

Analyse the open rates of previous email campaigns before selecting your subject line

Subject lines are no different.

Look at your historical email campaign performance to identify your most successful email subject lines.

Although we don’t recommend repeating old subject lines verbatim, you can use your most successful campaigns as a guideline when writing your new ones.

Spot the trends in your performance and think about why your subject lines have performed in this way.  Perhaps your contacts respond well to subject lines which pose a question or maybe an assertive approach works best.

Determine what it is that makes a difference to your campaign performance and test similar subject lines in the future to maximise your results.

Some Subject Line Ideas

For your comprehensive list of proven email subject lines, download our Subject Line Swipe File

Subject Line Swipe File

Download Your Ultimate Subject Line Swipe File

In this section, we look at some of the different approaches you can take when writing your next email campaign:

Pose a Question of Your Reader

Asking a question can help you start a conversation with your reader.

Take a look at these two examples from TGI Fridays:

TGI Friday Email Subject Line

The first subject line ‘The easy way to become Dad’s favourite’ is suggestive of the email content whilst the second email (a resend of the first email’s content) reminds the recipient to take action before it is too late.

The email acts as a timely reminder that the recipient will want to celebrate Father’s Day.  The question prompts the recipient to book a table.  We also notice that TGI Fridays have cleverly positioned a special offer in the preview text to give the subject line an extra push.

Instruct Your Recipient

The next subject line idea is slightly more risky.  Being too upfront with your recipients can come across in the wrong way.

However, if you manage to strike a balance between being assertive and friendly, you can expect to see your open rates soar.

Instructing your recipient to take action only works if the email recipient trusts the value of your content.

There is little point in telling somebody to do something if you don’t already have their trust.

Email Subject Line Trust Factor

Before you can be confident using a direct subject line, you need to build trust with your contacts

Successful examples of this type of subject line include:

  • Book your free demo today
  • Don’t waste time.  Find the perfect holiday for you

In each of the examples above, the benefit of taking action is clear making this approach extremely effective.

Taking the example we used above from TGI Friday results in a much more direct, sales driven approach:

  • Book your table for Father’s Day

Whilst this is more direct and does outline exactly what the recipient is expected to do, we prefer the original subject line.  Posing a question of the reader suggests that you care about the outcome – if the recipient hadn’t booked a table for Father’s Day, this email campaign acts as a timely reminder after the first email campaign.

Be Personal

One way that you can make your subject line different from the rest is to include personaisation.  Personalising email campaigns positively impacts email performance.

A personalised subject line uses one or more elements of customer data, such as the recipient’s name, to address the recipient with relevant information.

Reminding the reader of a recent purchase gives you the chance to rekindle any of the positive feelings that your customer felt the last time they dealt with your company.

One of our team recently received the following email from Easyjet:

Personalised Email Marketing Subject Line

This subject line is clever in two ways:

  • The use of the recipients first name is consistent across all the emails received from Easyjet, making their email communications more personable
  • The email is relevant to the recipient’s geography as Manchester is their local airport.

Highlighting both of these elements in the subject line immediately establishes the relevance and purpose of the email campaign even before it is opened.

Use Emojis

Emojis are becoming increasingly popular in email subject lines.  They convey a sense of fun and can be used as a visual aide in the inbox.

Of course, email inboxes are devoid of any visual cues so emojis are the only way marketers can include visuals before the email campaign is opened.

Emojis give your email marketing campaigns added personality in an otherwise text-only inbox. Do you use them? #emailmarketing #emoji Click To Tweet

Avoiding Common Subject Line Mistakes

When you are writing your email subject line, it can be tempting to fall into a number of traps.

The Overpromise

The first of these is to over-promise.

An email subject line that contains an elaborate promise will lead to poor email performance.

Yes, you might see a spike in your open rates but isn’t that just a vanity metric if your campaign is then sent to the bin, or worse, the spam folder?

Using phrases like ‘the ultimate’, ‘the greatest’ and ‘the best’ only work if the content matches up to the expectation you create.

It is sorely tempting to promise the earth in your subject line, only to reveal a subtle play on words when the recipient opens your email but it will backfire.

You will lose the trust of your email recipients and may never have the opportunity to rebuild that relationship again.

The Kitchen Sink

Email subject lines that try to conquer too much are just as bad as those which give no reason to open the email at all.

Trying to do too much with email subject lines

Trying to do too much with an email subject line is a bit like throwing the kitchen sink at it

They come across as confused and often detract from the message the email is trying to achieve.

If your email subject line is trying to cram in too many different elements, consider whether your email’s purpose is focused enough.  Sending an email with three or four different purposes in the hope that one sticks means that you haven’t segmented your email list well enough and your strategy needs some refining.

Decide on one main target that you want your email campaign to achieve and make sure your subject line reflects this.

The Negative No-No

Trying to play on your recipient’s emotions is fine unless you make them feel so negative or disengaged that they don’t open your campaign at all.

Don’t be an emotional drain on your contacts.

Instead, if you plan to use emotions in your subject line, ensure that you promote your product or service as the solution to their problem.

We think a negative subject line is a big risk to take.  Whilst it might work for some of your contacts, we think its too risky at scale.

Being Too Vague

You need your recipient to have a clear idea of what your email is going to say before they open it.  You can’t give all the details they need to make a decision – otherwise there would be no point in writing the email itself.

Yet, the subject line should be seen as your opportunity to give your recipient a clear reason to open.

  • Why this is your perfect opportunity
  • Get your discount today
  • Fill out your survey to win

In each of the examples above, the context of the email isn’t clear.  They lead you to ask questions such as:  The perfect opportunity to do what?  A discount for what kind of product/service?  What can I win?

Make sure you are crystal clear from the outset to make the right impression with your subject line.

Measuring Subject Line Success

Once you have chosen the perfect subject line for your email campaign, you need to monitor key email metrics to measure its success.  The clearest indication of subject line performance is your email’s open rate.

The open rate demonstrates the number of people who thought your campaign was worthy enough to take a look at when they saw it in their inbox.

The average email open rate across marketing emails in 2017 was 14.2%

This statistic demonstrates just how hard it is to get your contacts to open your marketing campaign.

You should also keep a close eye on your email spam rates.

Testing Your Subject Lines

You can use split testing to test the performance of your subject lines to a segment of your email marketing list.

No matter how good you might think your subject line is, you don’t have an objective measure of its effectiveness unless you test it.

Make sure that the email you send receives the highest number of opens possible by optimising your subject line content each time you send.


Writing the best email marketing subject lines relies on a good combination of creativity, using performance data and personalisation to make emails stand out in increasingly croweded inboxes.

Let us know how you come up with your email marketing subject lines in the comments!

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