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How To Master Email Marketing Subject Lines

Email subject lines featured image

You’ve spent much time composing the ideal email marketing campaign. You’re excited to share it with your subscribers! Now, all you need is one more step that may make or break your campaign—creating attention-grabbing email marketing subject lines.

Why are subject lines important? These will dictate how many subscribers actually open your emails, known as open rate. Email open rate is a key performance indicator (KPI) that all email marketers try to improve. It is calculated as a proportion of total subscribers who have opened an email. The subject lines of your emails are arguably the most critical component. After all, it is the subject line that subscribers see in their inbox that decides whether or not they open your email.


Email Marketing Subject Lines: Grab Attention

An effective email begins with a subject line that captures your readers’ attention. Great subject lines come in different forms and sizes, but they are all designed to entice your readers to open your content. Whatever approach you take, it’s critical to keep your audience in mind and test various words and phrases to determine which ones they prefer. Indeed, according to a recent survey, 47% of marketers test multiple email marketing email subject lines in order to maximize their emails’ effectiveness.

Whereas writing a subject line may be easy, identifying the successful email marketing subject lines is far trickier. That’s because it can be hard to predict which kind of subject lines: brief, humorous, detailed, and so on, would elicit the optimum response from your target audience. As a result, you should definitely experiment with a few various email subject lines in order to discover the best one for your audience.


Email Marketing Subject Lines: Trial And Error

Trial-and-error is a simple yet powerful technique to determine what subject lines will perform the best. Even large corporations depend on trial-and-error. After all, it’s almost impossible to predict which email marketing subject lines will strike gold for your subscribers. So, don’t be afraid to mix things up! For example, you may experiment with personalized, catchy, emotional, and funny subject lines to see which perform best. Additionally, you can combine your subject lines with emojis or say something surprising to see how it works in terms of open rate.

A/B & Multivariate Tests

Email Marketing Subject Lines: A/b Testing

This is a more complicated method of determining if your email marketing subject lines are likely to succeed. To begin, take a look at your most recent subject line performance. Then, use an A/B or multivariate testing feature in your email builder to determine the effect of alternative subject lines on your open rates. A/B and multivariate testing demonstrate the effect of tiny variations on performance and help identify which contacts like what. That will allow you to segment your audience into different groups so you can target them with appropriate email subject lines.

Numerous sophisticated email marketing campaign builders, such as Sendinblue and MailChimp, have this functionality.

What does a/b testing look like in practice?

Depending on how many contacts you are sending an a/b test to, you could structure it by sending subject line “a” to 25% of your contacts, and subject line “b” to another 25%. Then, use the more successful subject line for the remaining 50% of contacts.

Best Practices

Clearly, there is no one-size-fits-all approach for email marketing subject lines. Several famous tactics, on the other hand, have been shown to be successful. Bear in mind that subject lines are basically the only thing your readers will see prior to clicking through to the email (other than preview text & from name), so you must maximize their impact.

The following are a few tactics and best practices that email marketers employ to optimize their email marketing subject lines’ performance.


Email Marketing Subject Lines: Personalize

Personalize your subject lines with the recipient’s name or location using merge tags. Personalization has been demonstrated to enhance open rates for the majority of users and may be particularly effective when paired with targeted automation such as birthday specials and post-purchase follow-ups. The goal is to instill a sense of specialness in the receiver.

Example: “I’m sure YOU’RE going to enjoy this [first name]!”

Example: “[first name], I Applaud YOU For Being Awesome!”

Keep it Brief

A solid subject line accomplishes the task in 40 characters or less. Nearly 77 percent of emails are viewed on the phone, so a lengthy subject line may be clipped on mobile if too long. Also, the reader may miss critical information or get disinterested.

Example: “It’s finally here!”

Example: “We need to talk”

Make it Relevant

Email Subject Lines: Relevant

Relevant email marketing subject lines deliver the appropriate message to the right people at the right time. Create timely material that is tailored to your reader’s interests and wants. You may also have to test out what subject lines are most effective at a given time of day. This differs depending on your industry and subscriber demographics. Subscribers want timely and relevant information, and that is precisely what you should provide. The bottom line: the subject line must be relevant to the subscriber for them to even consider clicking through.

You’ll have a much easier time delivering relevant subject line if you do a good job segmenting your email list based on the different things the contacts have in common.

Example: “What they do in Denver at night”

Example: “Uh-oh, you’re low on stamina”

Create a Sense of Urgency

Email Subject Lines: Urgency

Utilizing urgency is a time-based strategy that normally succeeds because it encourages the reader to act immediately. This could be due to the short time that a special offer is active, or due to a limited quantity of inventory. Either way, people are more likely to act if there is a sense of urgency. You can convey a feeling of urgency by using words such as “limited-time deal” or “before supply runs out.”

Example: “Decision time…Do not miss this opportunity!”

Example: “Sold out in less than 30 minutes, but there is still hope!”

Avoid Using Spammy Phrases

Email Marketing Subject Lines: Spam

While it may be tempting to include terms such as “free,” “deal,” “offer,” “cheap,” “discount,” and “freebie,” your email may end up in the spam bin. This might also be detrimental to future campaigns. As a result, avoid too spammy language. And, don’t make promises you cannot fulfill. Readers are aware of clickbait and can easily label your email as spam. In addition, make an effort to avoid using exclamation marks or capital letters too frequently. Generally, people are not as hyped about your email as you are.

Example: “Is this the hottest ring you’ve seen?”

Example: “Welcome to your next favorite thing”

Inspire the Reader’s Curiosity

Email Subject Lines: Curiousity

Curiosity is a wonderful thing. Include material or substance that will trigger the reader’s curiosity. Curiosity is an inherent characteristic of human cognition. Unique or unusual email marketing subject lines may be just what your readers need to open an email. You do not need to go crazy; just discover a simple technique to draw their interest.

Example: “We accomplished the thing”

Example: “You won’t believe THIS happened…”


Email Subject Lines: Mobile Friendly

More than half of your users access emails using mobile devices. The subject line settings vary according to the device. Maintain a subject line length of fewer than 40 characters to ensure that it is viewable on all devices.


Email Subject Lines: Humor

A compelling subject line may also be creative — and perhaps even a little amusing. Bear in mind that these are not rigid guidelines. Your audience will tell you what works and what doesn’t via their clicks. Therefore, utilize these suggestions as a starting point, but always test your subject lines to see what works best for you (and for your subscribers).

Example: “Life keeps coming. And so do freebies!”

Example: “It’s that dang time of the year!” 

To summarize, try various strategies in order to gain the benefits of strong email marketing subject lines. And don’t forget that manually measuring your open rates and campaign performance is impossible. Numerous tools exist to assist you in analyzing your open and clickthrough rates, segmenting your audiences, and doing A/B or multivariate testing on your subject lines.

Want more information on how to write amazing subject lines? Check out Dan Lok’s video on 7 Subject Lines That Get Your Emails Opened.

Now that you’ve mastered email subject lines, you might be interested in reading all about the optimal email designs. Afterall, what good are open rates if you can’t get your subscribers to click on your emails?T

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