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You’ve been struggling to write the perfect email for your recipients, only to discover that just a small percentage of them are responding to your offers, or even looking at them. With no one reading your messages, you’re losing thousands of potential clients every single day. What could you possibly be doing so wrong?

While a number of factors go into the failure or success of your marketing efforts, you may be overlooking one seemingly small element: your email subject lines.

The Importance of Email Subject Lines

The purpose of your email subject line is to get your email opened, right? Wrong! If you only want your email to get opened, then don’t even bother writing a subject line. Your odds are way, way better that way. In fact, blank email subject lines are opened 8% more!

But there’s a caveat to that. According to Sappleton & Lourenco (2015), blank email subject lines would significantly improve your email response rates, but not necessarily in the direction you want them to.

Surprisingly, those blank email subject lines were opened and responded to by the recipients when they were invited for a survey. However, they responded only to reject participation! The blank subject line is a good bait, but it probably won’t get the response you want. So, what should you do? Write a great email subject line, of course!

The Purpose of Email Subject Lines

The main purpose of your email subject line is to get the recipient to open and respond to your email, and you’ll do that by giving them context to properly set their expectations.

Clearly, if you want your recipient to read an article you recently published, it would require a lot more time to read about 100 ways to save money than just 5 ways. Your subject line should prepare your recipient so they’ll know how much time and attention they need to give to your material.

In other words, your subject line is a set-up, a primer to make the recipient more open to whatever call-to-action you include in your email.

Note: Remember to avoid creating emails that look like spam. According to another study, 47% of your recipients will decide to open your email based solely on the subject line, and 69% will use it as a deciding factor to report your email as spam. To avoid your email from looking like spam, you can try utilizing tools that will check your spam rating.

Tips for Writing Effective Email Subject Lines

“Treat your subject line like the movie trailer—give a preview so they know what to expect.”

Create a Sense of Urgency

Urgency! Urgency! Urgency!

Unless you’re Jeff Bezos, and all you need is to write “?” in your subject line to set off alarms in your recipients, you’ll benefit greatly by trying to create a sense of urgency. In fact, subject lines that include urgency and exclusivity have 22% higher open rates

Here are some examples:

  • 50% Discount for premium membership until July 12 only!
  • Get 20% off of your purchases for today only
  • Quick! Only 50 slots left for the upcoming webinar

These kinds of subject lines work because they trigger the human desire to avoid loss, or what we call loss aversion.

When you feel something is scarce and you’re missing a great opportunity, it can be uncomfortable. Your recipients already know how to make this feeling go away — click!

Surprise, Surprise!


The human brain loves novelty, so use that to your advantage. Present something unexpected to capture your recipients’ attention. After all, the brain loves the unexpected (unexpectedly pleasant, of course).

In fact, the brain finds unpredictable pleasant things more rewarding than predictable pleasant things regardless of what people say they like. So why not make your email a pleasurable experience?

Here are some examples:

  • How to get more done by taking a nap (Foundr)
  • The art of trying hard effortlessly
  • How I lost weight by eating more

You can also try adding a little humor to your subject lines. Creating a mismatch between expectation and reality can lead to humor, so establishing this mismatch is the secret sauce of all things humorous.

However, beware of the risks of attempting humor, and make sure to look at the full context. You don’t want to make jokes that would offend your recipients and kill potential business.

Be Relatable

As humans, we like to connect with others. In fact, belongingness is one of the fundamental psychological human needs. So a message tends to be particularly effective when we can feel that the other side speaking to us is another human being.

Don’t be afraid to share a little bit about yourself. Share your pains, how you learned from them, and use them as reference in your subject line to pique their curiosity. This will make your audience more likely to engage with your message.

Showing that you are human who makes mistakes will help others connect with you. People love the struggle and love to hear about others who went through the same hardships and challenges that they did.

Here are some examples:

  • The mistake I made that cost me thousands of email subscribers
  • How I lost thousands of dollars trading stocks
  • How I wasted thousands of dollars on advertising

Be relatable. Be human. Don’t be afraid to connect with your audience. It works.

Offer Something for Free

Many people are willing to wait hours in line for free stuff.

Just by offering something for free, you can increase your email open rate by 10%. That’s because as human beings, we’re suckers for free stuff. Take this one study by Dan Ariely for example:

We offered students a Lindt Truffle for 26 cents and a Hershey’s Kiss for 1 cent and observed the buying behavior: 40 percent went with the truffle and 40 percent with the Kiss. When we dropped the price of both chocolates by just 1 cent, we observed that suddenly 90 percent of participants opted for the free Kiss, even though the relative price between the two was the same.

Such is the power of free stuff. Even more interesting are the examples given by Eva Kockrow, which show that people are willing to queue for long hours just to get free donuts! When you think about it, it’s nuts! People are willing to spend hours of their life waiting just to get free things, even if those things are normally already very affordable!

If they were iPhones, it would’ve made sense. But donuts? Very interesting! Another related phenomenon is people who willingly subscribe to email lists to access free content. If people are willing to go to these lengths to access free stuff, just imagine if all you want them to do is read your email!

Here are some examples:

  • Buy one, get one free
  • Sign up for your free personality report
  • Sign up for free expert cybersecurity consultation

So why does free stuff work? Enter the Zero Price Effect. Basically, it’s what we call the phenomenon illustrated above in Dan Ariely’s study.

Free goods have extra power. A price reduction from $1 to $0 is better than a price reduction from $2 to $1, despite the same reductions in value. This extra power is explained by the affect heuristic, where things with no downside (like things that are free) trigger a more positive response.

Another possible explanation is loss aversion. Paying for something with your hard-earned cash incorporates some risk, or the potential to lose something (like buying a product that turns out to be disappointing).

Free products would bypass this risk, since there’s absolutely no risk incurred by the consumer, at least in terms of money (remember the time you spent queueing for that donut?).

Note: Offering something for free is a common marketing strategy. You might have even received a few offers yourself. To avoid looking like spam, you can describe the kind of value that people will get from your offer (e.g., “These four worksheets are ready for you to use now”). This describes the value while implying that it’s free, without directly stating it.

Use the List Formula

Write that list!

Remember, your email subject line must arouse curiosity while providing context to set the recipients’ expectations. Writing a list is a great way to easily accomplish this goal.

Telling your recipients how long the list is (5, 10, 15, 25 items) would prepare them for what’s to come. In this way, they are mentally primed to consume the material, be it a long read or a short one.

Here are some examples:

  • Top 10 reasons why you’re not improving in chess
  • 50 must-know techniques of every digital marketer
  • 3 writing secrets of Ray Bradbury

Although longer lists don’t always mean longer reading times, just looking at the number 50 would immediately prime your recipients that what they are going to read will take more than a minute of their time, while 3 items seems like it might take only a minute.

Ask a Question

Why Ask?

Why should you ask a question in your email subject lines? Simple: questions generate curiosity. Asking a question stimulates your recipient’s brain to generate a response. Notice how you, even for a moment, tried answering the question in this paragraph.

Even if you did not, you would probably expect the sentences that followed to answer the question. Your brain was therefore primed to generate an answer, whether by thinking or by reading.

It goes without saying that the content of your email must be related to the question you’re asking. Otherwise, it might damage your brand or reputation.

Challenge your recipients. Ask where they stand on things. Surprise them. Be creative about it. As you should know by now, your email subject line is almost half the battle. The most valuable offer will never stand a chance if it never gets read.

Here are some examples:

  • Myers-Briggs Type Indicator (MBTI): Science or Pseudoscience?
  • How can you grow your conversion rate in three simple steps?
  • How to create your portfolio without any writing experience

Always keep in mind that your questions should be open-ended. You don’t want your recipients to see your email subject line and say to themselves “no” and click “delete.” If it’s closed-ended, make sure that it would be intriguing enough or something worth answering for your recipients.

Reference Authority Figures

“Follow an expert.” —Virgil

Who do we go to when we need medical assistance? Doctors. Legal problems? Lawyers. Mental health problems? Psychologists. We solve most of our problems by adhering to the advice of the experts around us. After all, the opinion of someone who studied a specific subject for thousands of hours is much more likely to be accurate and reliable than our own opinion.

This concept is intuitive and easy to grasp, but there’s also science behind it. In Robert Cialdini’s book Influence, one of the principles of persuasion he discusses is Authority. In one example, real estate agents recommended their reception staff based on their expertise and credentials:

Customers interested in letting a property were told “Lettings? Let me connect you with Sandra, who has over 15 years’ experience letting properties in this area.” Customers who wanted more information about selling properties were told “Speak to Peter, our head of sales. He has over 20 years’ experience selling properties. I’ll put you through now.”

The result? A 20% increase in the number of appointments, and 15% increase in the number of signed contracts. Not bad, right? If you are expecting your recipients to open your email and respond, using authority figures is one of the best techniques. Knowing what an expert has to say about their expertise is probably more valuable than someone without any credentials.

Here are some examples:

  • How Adele learned to sing
  • How Bruno Mars wrote “Versace on the Floor”
  • Magnus Carlsen explains how to improve in chess

Just think about those examples for a moment. Wouldn’t you want to learn how to sing from the leading singers of the music industry? Wouldn’t you be interested in learning how to play chess from the current World Champion himself? So whenever you struggle with your email subject lines, follow the experts.

More Tips

The following tips are not directly related to the construction of your email subject lines, but they are important considerations for improving your outcomes.

Show the Face Behind the Message

Do you know how long it takes for a person to judge you? One tenth of a second. That’s right. In the blink of an eye, people will judge whether you are attractive (better outcomes for attractive people) and whether they can trust you or not.

So make sure you look as professional, trustworthy, and responsible as possible. Why? Because if people don’t trust you, they won’t open your email, and they definitely won’t respond. Poof! All your prospects and potential business are gone. So take your time choosing a profile picture, because second chances are hard to find.

And don’t even think about not putting an image. Just consider what you would do. Who are you more likely to open an email from: someone with a good-looking, professional picture that reflects the brand he/she is speaking from, or that email with a sketchy default Google image?

Another reason to put your profile picture is to help your recipients identify that they connected with the right person. Your name might be too generic (you’re surely not the only James Smith in the world), so they might end up confused.

Lastly, make sure to use your profile picture to reflect your brand and your intentions when you send a message using that email. Is it for professional purposes? Look professional. Fun brand? Fun photo! Creative brand? Creative photo! The possibilities are endless. Before you start posing for that picture, here are some rules worth considering.

Consider Your Capitalization

NEVER EVER WRITE YOUR SUBJECT LINES IN ALL CAPS! It feels like you’re shouting, and statistically speaking, the odds of your email getting opened would significantly drop.

According to Boomerang, response rates to emails with all caps in their subject lines are 30% lower than those without. Even worse, your message may not even reach your recipients’ inbox, since writing in all caps could make it more likely that your email is marked as spam. So how should you write your email subject lines?

Syntaxis provides two options:

1. Capitalize your subject lines as if it’s a title. Begin Everything in Capital Letters Except the Minor Words.

2. Capitalize your subject line as if it’s a sentence. Capitalize your subject lines like this sentence (capitalizing just the first word).

So when in doubt, choose one of those two recommendations.

Note: Avoid weird caps. yOu dOn’t WanT youR subJect linE to Look liKE thIS. Not only is it hard to read, but it’s also annoyingly immature and unprofessional.

Consider the Length of your Subject Line

Experts differ on exactly how long subject lines should be. However, the sweet spot appears to be around 6-10 words.

Avoid making subjects too short or too long. Moreover, take into account the kind of devices or email platforms your recipients are using, since there are variations in terms of characters displayed in subject lines.

Consider Your “From” Line

According to Robert Bly’s Digital Marketing Handbook, the use of From lines depends on who you are sending the email to.

If your recipients are from your own opt-in list, use your name or your company name, or both (John Watson, Google). However, if you are emailing from a rented list or affiliate list, it is better to use the list owner, which would then introduce you in the body of the email (“Here are some giveaways from our friend John Watson at ABC Company”).

Consider the Context of Your Email

Before writing your email subject line, consider the context in which your email will be received. If you are applying for a job position, a simple, straight to the point email would suffice.

Example: “Your Name – Application for [Position you’re applying for]”

By doing this, they already know that your email is business-related, and not just clickbait or someone trying to get their attention to sell them something. When you mean business, keep it simple and straightforward. This way, they immediately know that your email is important and worth checking out.

Email Subject Line Formulas

To expedite your subject-writing process, here are some generic formulas to inspire you. However, be sure to always customize the subject line in a way that best serves your goals and reflects your business.

  • Use this secret tactic to improve your [outcome]
  • [X]% of [Practitioners] love this [product]
  • [Recipient’s Name], [Message]
  • [X]% discount for [Product] until [Date] only
  • You might be committing this [topic] mistake
  • How I learned to [skill] without [difficulty] in [specified time]
  • Sale: [Product] [Discount]
  • Sign up for free [report/product]
  • [Number] must-know techniques of every [practitioner]
  • Here’s a free [worksheet, report, etc.] for you
  • These [product/s] is/are ready for you to use now.
  • How to [do something] without [difficulty]
  • Save [discount] on [product]


This is not mandatory, but it’s a good way to find out what works. You can try a split test, where you divide your email list in two groups and send one version of your subject line (Subject line A) to one group, and another version (Subject line B) to the other group and compare the results.

You can also try using different time frames. For instance, you can send a single version of your subject line to the whole list, and then send another version to those who did not reply after a certain period and see if it improves your open rate.

By practicing the tips in this post and figuring out which styles work best for you, you can make sure that your carefully crafted emails actually get read—and answered!

Did you find this post helpful? Let us know in the comments below!


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