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INSIGHTS Top 16 email subject lines to increase your open rate

13 May 2021

5 minute read

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Whoever said you should never judge a book by its cover did not consider email marketing! 

With mountains of insights from A/B testing and data analysis we know that the right (or wrong) subject line can make or break an email campaign. You may have Nobel-prize winning articles or the best product discounts within the email but what use are they if no one is actually opening it?

So how can you cut through the clutter in a customer’s Inbox and make sure your email gets seen?

A solid email marketing strategy is of course vital before you start hitting the virtual doormat. By the time you’re ready to select your subject line, you should hopefully have already thought about the following:

  • Audience - who are you talking to?
  • Content - is it relevant to that audience?
  • Testing - how does your email actually look and perform on different devices such as Android vs iOS vs Desktop?

Now you’re ready to find that winning subject line! There are also numerous free subject line checkers available online, and many of the top email marketing providers will also offer you the option for A/B testing. Often this means that your provider will ‘learn’ which email is performing best and then prioritise that over the other. Nifty.

But, let’s not leave it all to chance or algorithms. Here are 16 of our tried and tested ‘themes’ that make up many of the most successful email subject lines.

1. Me, me, me

Self-interest should definitely be at the top of your list when it comes to subject line ideas. Knowing your audience and their interests is key here to delivering content that will benefit them by opening the email.

Example:
The moisturiser that makes you look 10 years younger! 

2. Curiosity

Pique your recipient’s interest by teasing them with a mystery that can only be solved if they open your email! Just be careful to ensure that your content within is relevant to the subject line - no one likes to feel tricked by clickbait.

Example:
I got Botox—and this is what it looked like
Well this is awkward

3. Social proof

This is a little bit like a friendly referral. Many of us don’t want to be the guinea pig when it comes to trying something new, and knowing that someone has gone before us with positive results can be a marketing winner.

Example:
See why 100,000 other parents have already bought this buggy!

4. Humour

Who doesn’t love a good laugh? Funny subjects can really help to stand out in an Inbox full of marketing emails and spam. Just ensure you know your audience to see how far you can push it!

Example:
If you enjoy paying full price this email isn’t for you

5. Urgency

This is a very common email tactic and used sparingly can be highly effective to motivate someone to act fast.

Example:
Sale ends in 12 hours!

6. Fear Of Missing Out

Argh the dreaded FOMO! None of us want to be the only one out of the loop on the latest cool trend, so playing on this human trait is a clever way to engage with your audience.

Example:
The dress every fashionista is wearing this season is nearly sold out!
Only 10 tickets left!

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7. Amazing offers 
Who doesn’t like free or cheap stuff?! If your deal is good enough, be loud and proud and make sure to add it into your email subject.

Example: 
50% off our bestselling jumpers!

8. Lists and numbers
Who doesn’t love a list? This is a great way to get someone’s attention and let them know what to expect from your email.

Example:
Top 10 email subject lines to increase your open rate (sorry we couldn’t resist)
25% of all parents admit to doing this

9. How-to’s
We don’t have all the answers all the time, so relying on the experts to help us out can be a winner subject line. But make sure if you are offering advice, that you’re in the right position to do so!

Example: 
How to bake the perfect pizza dough with only two ingredients 

(*seriously email us - this is the best recipe!)

10. Does what it says on the tin
Sometimes we need a little clarity in our lives. Enough said.

Example:
Order by midnight for free next day delivery

11. Attention grabbing/shocking
This strategy can certainly grab someone's attention - just make sure it’s for the right reason. So do your homework, know your audience and consider your approach so you don’t end up offending or alienating anyone.

Example:
Your marketing sucks
Does your kid know more about technology than you?

12. Personalisation
By personalisation we don’t mean ‘Hey Bob’. In fact it’s the opposite - these days adding names has become so over-used these emails often get marked as spam instead. No, we mean knowing your audience, what do they love, where do they live? Think about something that shows you know and understand them.

Example: 
Are these the best pizza restaurants in Hampshire?

13. Be timely
There’s always a risk element to this type of email - if someone misses it in their Inbox then it may not be so relevant three days later. But get it right and it could send your open rate soaring!

Example: 
Check out the hottest bars to hit after work today!

14. Question and answer
This is where you speak to someone’s interests, or even their problems or anxieties. The key though is to always provide an answer or solution within the email. That way you’re enticing them to open, but by offering a resolution you’re also making yourself an invaluable resource too.

Example: 
Are you struggling to find the perfect family staycation?

15. Short and sweet
We’re all short on time these days, so often single words or short, snappy phrases can stand out better. In fact, research suggests that email subject lines should be no more than 9 words and 60 characters long.

Example:
Wow
Too good to miss

16. Command
This is digital marketing after all, so be direct and give your customers some actionable directions that will lead them to engage.

Example:
Enter our competition now to win a car!
Tell us what you really think

So there you have it. Use these handy tips to kick-start your email marketing campaigns. If you ever need a hand though or just a bit of advice then you know who to call, we’re always here to help.

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