How to Increase Email Open Rate: 42 Expert Tips

Subject Line Freshness is the Key

– “Subject lines… the easiest thing to write, the hardest thing to get right. There is just no single best practice, rule or tactic that works every time.

Emojis and symbols might produce killer email open rates one week, but that doesn’t mean every subsequent send should be jam-packed with ☀☀☀ and ☺☺☺. You have to keep your email subscribers on their toes.

The key is freshness in moderation. But how fresh and how much moderation?

“To improve is to change; to be perfect is to change often”
Winston Churchill

Email Marketers are Not Using Fresh Subject Lines

Team Alchemy Worx analyzed data within subject line testing tool, Touchstone.

Touchstone contains open, click and delivery rate data on subject lines from over 1 million subject lines sent over 1 trillion times across various sectors and industries. It uses this data to predict how other subject lines will perform, so marketers can find simulate tests and find the best subject line for their email campaign. In this case, the team used the wealth of data contained within Touchstone to identify how many subject lines could be classed as fresh, and how many were stale – fresh being a subject line that contained at least one word the sender had never used before.

You might think that with such a conservative definition for freshness, most marketing emails would be classified as ‘fresh’. But as the pie chart shows, less than a third were classified as fresh.

Fresh Subject Lines Boost Click Rates

So what effect does freshness have on open and click rates? The results are below:

While we only see a modest increase in email open rates when using fresh words, we see a significant lift – 34% – in the unique click rate. So what’s happening?

Using fresh subject lines triggers an entirely different subset of subscribers to open your emails – “Oh, this doesn’t look like the weekly newsletter I usually ignore”. And since first-time openers and long term inactives are more likely to click than regular openers, the click rate goes up.

This also explains why the open rate does not increase as much as the click rate. Fewer regulars opened the email, but more irregulars did. And since irregular subscribers are more likely to convert following an open, the click rate is improved.

Freshness is About More Than Vocabulary

But it’s not just the words themselves that contribute to freshness and variety. The way the message is presented is just as important. These are called tactics. Look at these two subject lines about a re-brand:

• Celebrate our new look with a 10% saving on Apple, Sony & Coke
• We’ve changed – take a look!

They are different because they use different tactics. The first is a long, specific, multi proposition with a discount and brands. The second is short and intriguing.

It’s a common goal of A/B split testing to identify the tactic that works best. We have found this often only tells you which tactic worked best for that email campaign and that attempts to repeat it offer diminishing gains.

Here are the last two years’ of Alchemy Worx emails broken down by 15 common tactics.

With one or two exceptions there aren’t significant differences between the tactics. That’s because there is no single tactic that works all the time. It’s the change in approach that yields results and naturally these even out over time. And when you do find big differences, think of them as opportunities – so we should probably use symbols a little more and not worry about personalization!

Use Tactics to Write More Varied Subject Lines

So, even though there is no golden tactic that works every time, the tactics themselves provide a structured framework for writing varied and fresh subject lines. Take the 4 subject lines below for the same re-brand e-shot and 10% discount:

• Enjoy a 10% discount and check out our new look
• Get a 10% saving and see our new website
• Save 10% and take a peek at our new brand
• Here’s a 10% off code to celebrate our latest refresh

The only changes here are to the vocabulary. Here are 15 different ways to write this same message using some of the most common subject line tactics:

Short – Under 60 characters including spaces (keep it concise)

• Celebrate our new look with a 10% saving

Long – Over 80 characters including spaces (you can add more personality and detail)

• Help us celebrate our brand new look and enjoy 10% off as a thank you for your support

Single Proposition – Mention only one part of the content of the email

• Check out our new look!

Multi Proposition – See our new look, have 10% off and check out our hilarious new blog post and video

• Check out our new look!

Brands – Use brand names in your subject line (if appropriate to you)

• See our new look and enjoy 10% off Apple, Sony, Coke and more

Symbols – Use symbols (if appropriate)

• Celebrate our new look with a 10% saving ☺

Promotional – Get the promotion in, preferably up front

• Enjoy a 10% discount and check out our new look

Personalization – Use personalization (name, product, location, etc)

• ##name## see our new look and have 10% off

Question – Use a question, preferably open (i.e. the answer can’t be yes or no)

• We’ve got a new look so what will your celebratory gift be?

Urgency – Add urgency with a specific time or limited time message

• See our new look now and enjoy 10% off today

CTA – Add prompts and imperatives to do something

• Open up, check out our new look and claim your 10% discount

Benefit – Say how your customer will benefit from the content of the email

• See our new look, get 10% off and get your new look for less

Negative – Phrase in a negative way or use a negative emotion (loss v gain)

• We’ve changed but hurry or you’ll lose your 10% discount

Intrigue – Don’t give away the content of the email, make them open to find out

• Look – we’ve changed!

Specific (no reflection) – Say what’s in the email or be clear about the content

• We’ve got a new look and you’ve got a 10% discount

For each tactic, there will be many different ways to convey the message and still remain within the style of the tactic. You can play with the word order, change the tense or use a thesaurus to find different ways to say the same thing. You can also combine tactics. Here, small tweaks and additions to multi-tactic subject lines make subtle but noticeable differences:

Short + Single + Brands + Question + Urgency + Benefit

• Do you want to look sharp in Armani today?

Short + Single + Brands + Question + Urgency + Benefit + Negative

• Don’t you want to look sharp in Armani today?

Long + Single + Promotional + Personalization + Negative + Intrigue

• Dan, bet you never thought you’d see these five huge brands with a 10% discount

Long + Promotional + Personalization + Negative + Intrigue + Brands + Multi

• Dan, bet you never thought you’d see Armani, D&G and Channel with a 10% discount

Again, it’s important to remember that the tactics are being used as a framework to write varied and interesting subject lines, not to find which tactic works best for you. All of these tactics will work for you at some point, just as all of them will fail at some point. Once you are comfortable with the tactics, then writing 10, 20 even 30 fresh subject lines on the same topic should become 2nd nature. And it’s that variety that is the key to a subject line strategy that embraces constant, strategic change.

Finally, once you settle on a particular tactic for the next mailing, make sure to test your options using Touchstone. It will instantly identify the best performing subject line, saving you valuable time and resource in your quest to boost engagement and maximize revenue.”