How to write the best email subject line: 11 tips

Email marketing can be incredibly powerful for your business, serving as a tool to communicate with customers worldwide.

However, it is only valuable if you can find a way to engage your recipients and get them to take the appropriate action – usually a click to your website where they can progress their buying journey.

This starts by getting their attention and encouraging them to open your email and not send it to the landfill of their deleted folder.

If you can’t get them to open it, any energy put into crafting your email campaign is wasted, and you’re unlikely to experience any return on investment or other rewards for your efforts.

Your subject line is crucial when engaging your recipients and getting them to read your emails. It can be the difference between them press the open or delete button.

We’ve listed our top tips for creating an excellent subject line that makes sure you get the results you want from your email activity.

• Why does your subject line matter?
• 11 subject line writing tips

The subject line is the first thing a recipient sees when receiving an email. It’s also one of the only things they see until they open the email, alongside your email address, sending time, and preview text.

As such, your subject line is one of the main factors in determining if someone opens your email or even deletes it. With countless other emails usually in an inbox (at work alone, the average person receives 100 emails per day!), you need to make sure yours stands out from the crowd and wins over the recipient’s attention.

By ensuring your subject line is effective, you can encourage customers to consistently open your emails and digest what you have to say. This should also drive your other metrics, including website traffic, conversion rates and sales.

Understanding how crucial a subject line is to the success of your email campaigns, you need to learn the art of writing an exceptional one that captures attention. We’ve listed our best tips to help. 

1. Keep it short

The optimal length of a subject line is reported to be six words or less than 50 characters.

While there’s no set limit, if you create a subject line that’s too long, the email provider may omit part of it, causing meaning to be lost. That’s why it’s best to keep it short and snappy.

Even if it doesn’t necessarily fall under 50 characters, you should still aim to be succinct and say what you mean.

2. Be relevant

A subject line should highlight exactly what a reader can expect to find in the content of an email and whet their appetite to find out more.

Don’t be tempted to choose a flashy subject line if it does not reflect what lies within the email body. This is disingenuous and can harm your customer relationships, making them unlikely to purchase from you or open future emails.

Instead, focus on finding memorable ways to showcase the content in your email so someone opening it gets what they expect.

3. Be catchy

A common way to capture attention is by crafting a catchy subject line that remains in the minds of your audience. This makes them more likely to click open.

There are many ways to be ‘catchy’, including:

• Using alliteration (e.g. “Grab a great deal today!”)
• Use power words, such as ‘bargain’, ‘instant’, ‘limited’ and ‘final’
• Use words or phrases that your recipient might not expect
• Convey a sense of urgency (e.g. “Time is running out for this exclusive offer!”
• Use conversational or informal language, like the example below from My Protein.

Use these ideas to brainstorm a variety of subject lines and explore which work best for your audience. There are a few other ways to stand out in an inbox, which we’ll delve into deeper.

4. Keep it simple…

One method for optimising your subject lines is keeping things simple. For some audiences, the lines that work best are straight to the point. These work well for transactional emails, letting the recipient know what you are saying at a glimpse.

With a simple subject line, you should say the primary purpose of the email, which can then be expanded on within the email body. You could even include the call to action directly in the subject line.

5. … or stand out!

While simple is best in some scenarios, sometimes you need to do the opposite: stand out!

Ways to stand out include utilising humour, exaggeration, shock tactics or intrigue. We’ve included some real-life examples below.

In this subject line, Etsy uses the simple word ‘Psst…’ to make the reader want to discover the secret. It also suggests exclusivity.

In this example, selling goods for Mother’s Day, the brand uses the pun ‘mum-mentous’ to jump out to the audience. It creates a light-hearted feeling which could also improve sentiment towards the company.

This example utilises shock tactics with the word ‘DINOSAURS’. This goes against what the reader might expect to see from a regional magazine, making them want to find out more.

Finally, exaggeration can make a reader more interested as it makes the content of the email seem like a big deal. In this example, the combination of capitalisation on ‘new’ and the phrase ‘are everything’ hypes it up.

Focus on just one or two tactic. The tips we’ve listed so far should inspire creativity, rather than be a checklist of what to include. Don’t try to cram everything in as it will usually make things confusing and overcomplicated!

6. Use numbers and characters

Another way to differentiate your subject line is to use numbers, emojis and characters. These break up the vast amount of wording sitting in most inboxes.

Only use characters and numbers if they make sense for your subject line. If you add them in for the sake of it, it can often come across as spammy. So, be selective in your use for maximum effect.

7. Understand your audience

Regardless of which tactics you utilise to optimise your subject line, the key to success is tailoring it to the recipient and their preferences. This means inherently understanding your audience and what engages them.

Take time to conduct audience insight that enables you to uncover their requirements. From here, you can craft subject lines that best appeal to them and secure you the open rate from the people that truly matter – your future customers.

8. Utilise personalisation

Another standard method to attract people to your emails is through personalisation. At a fundamental level, this means using ‘you’ and ‘your’ to address your recipient directly.

In the modern age, advanced personalisation has become more accessible, with many platforms enabling you to implement it into your campaigns easily.

However, it should be used intelligently. Personalisation is more than just adding someone’s name into a subject line – it’s about refining the entire email, so it offers them value.

Focus on what that customer needs at that time to progress their purchasing decision and offer an outstanding experience. In most cases, this will affect the content included in your email, which should filter down into a compelling subject line that piques their interest.

9. Match your brand voice

Another consideration when crafting a subject line is how it fits into your brand tone of voice. Most brands will have a TOV guide that dictates how they speak to customers while preserving their identity and creating the right associations.

Refer to your guide when crafting every part of your email to reflect the agreed way of communicating with your customers. This will enable you to maintain consistency across your touchpoints, which will allow you to build the reputation you want with your customers. 

10. Conduct A/B testing

It’s hard to know what subject line will work best until you send it. Even if something sounds good to you, your recipients may react differently.

Therefore, testing is essential to find the perfect formula for your subject line.

You should start by compiling a list of potential ideas for any email you create – we recommend at least 10. Then, you should refine it to a select few contenders, running them past colleagues to help you narrow things down.

Once you have your final subject lines, conduct A/B testing. If you have two subject lines, for example, this will involve sending 50% of your database an email with one variation of the subject line and the other to the rest of your audience. Aim to keep all other variables the same.

After you have sent out your emails, you can then check the results to see which subject line got the best open rate. You can then keep this in mind for next time.

If you conduct A/B testing frequently, you will eventually build a picture of what works for your audience and brings maximum results

11. Continually improve

Nobody creates their best subject line on their first or even 100^th attempt. It’s a process that requires time, patience and growing expertise.

You will continually improve by experimenting and testing your subject lines over time. Your results should get better too.

Continuing to test your ideas will enable you to stay on top of changing consumer behaviour and trends to benefit your open rates further.

Creating a great subject line is an integral part of the success of your email marketing campaigns. Your open rates should skyrocket with carefully considered wording that explicitly addresses your audiences’ preferences and grabs their attention.

Better open rates should then translate into higher clicks and conversions, which drive traffic, sales and profit.

You shouldn’t expect these results straight away – it requires work and time. However, the benefits make it worthwhile.

Our team can revolutionise your email campaigns to achieve the results you desire, starting with a powerful subject line that secures clicks. Get in touch with OM today to find out how we can help you.