2. Communicate the value of your email

A great email subject line succinctly communicates the value of the email content. Whether it’s an exclusive offer, breaking news, or valuable insights, the subject line communicates what the recipient will gain when they open the email. This value proposition can make the email more engaging.

3. Improve delivery rate

Email Service Providers (ESPs) use algorithms to filter out spam. A compelling email subject line can help your email avoid being marked as spam.

According to a study by Invesp, 69% of email recipients classify an email as spam based on the subject line alone. Since a well-written subject line is more likely to be relevant and engaging, it can determine whether an email is spam or not.

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It’s easier than you think. Add Hello Bar to your lead generation tools so you can invite website visitors to sign up for your email list .

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The formula for a compelling email subject line

We ’re going to give you 50+ engaging email subject lines , but first, we want to discuss formulas and why they work.

You might think that a formulaic approach to copywriting would be a bad thing. After all, don’t unique and eye-catching email subject lines get better responses ?

The answer is yes. However, catchy email subject line formulas can help inspire you. By filling in the blanks with a good description as below, you can get as quirky, funny, surprising, or insightful as you want .

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The category you need to fill in

The formulas we’ve developed for engaging email subject lines all have one or more categories that you need to fill in to suit your specific purpose. It’s a bit like a math formula. You plug in numbers for A, B, and C to balance both sides of the equation.

Let’s look at these categories so you know how to approach them properly. We’ll use a weight loss-related topic as an example to help you stay on track.

Positive results

When you think of positive outcomes in the weight loss industry, you think of losing weight and gaining muscle, right? You’re looking for insights you can share with your audience that show them the end of the road.

For example, your subject line might be something like: “How John lost 300 pounds in three years.”

This is a positive outcome. You are not revealing the full story—you are just hinting at it to spark curiosity and desire.

Negative result

Negative outcomes are the exact opposite. You’re calling out pain points here to help your readers better understand why a negative outcome occurred — or to help them prevent it from happening to them.

Your negative results subject line might be something like: “Why John tried to lose weight for ten years — and nothing worked.”

That statement—”nothing happened”—is your negative outcome. People want to know why.

Overall Theme

Your overall topic is a bit like a category title on your blog. In the context of weight loss, it might be dieting, exercise, motivation, or calorie counting. The overall topic could also be the main subject related to your business: weight loss.

The general subject line might look something like this: “Weight Loss: What You’re Doing Wrong.”

You’ve clearly stated the subject line so people know what to expect.

Controversial topics

We all love an argument, right? It keeps us up at night and forces us to think things through more thoroughly.

A controversial topic headline might be something like: “IIFYM doesn’t work.”

This is controversial because many people follow the “if it fits your macros” approach to weight loss. You’re taking a controversial stance and saying that doesn’t actually work. Just be prepared to back up your controversial opinion.

Target Market

When the compelling email subject line formula asks your target market, they are looking for the people who are most likely to buy your product. You are naming them.

Following my theme, a target market subject line might look like this: “Fad Dieters: Here’s What You’re Doing Wrong.”

You are calling out to a specific group within your target audience, people who might be interested in buying your product. Doing so helps you speak directly to your readers, as if you can read their minds.

Common objections

Wherever there is a goal or pain point, there will always be opposition.

For example, when it comes to weight loss, a common objection is that people don’t want to feel deprived. Dieting is both physical and psychological.

So your subject line formula with common objections might look something like this: “Tired of feeling deprived? Here’s how to bounce back.”

You address your objection directly and hint that you have a solution. Of course, you need to communicate this in the body of the email.

Year or Month

Using a year or month to quantify something in your email subject line can make it more impactful.

Consider this question: “Do you want to lose weight?”

The answer is probably “yes,” but not in any practical sense.

Let’s make it better: “Do you want to lose X pounds in X months?”

Now, let’s get started. This question quantifies the variables mentioned in the first question, which makes it more powerful.

Name of industry supervisory department

Mentioning the names of Jenny Craig or Robb Wolf can make email subject lines more effective in attracting dieters. You will receive an immediate response, whether positive or negative.

If you see “Industry Authority Name” as a variable in a subject line formula, it means you’re looking for information about someone who is well-known.

Trustworthy Sources of Information

The other side of an industry authority name is a trusted source. This might be a publication like Everyday Health, or an organization like TOPS, which frequently reviews topics like: Best EHR Systems for Small Practices .

You can use citations as starting points or data points.

Contact Number

As we mentioned in the section above about month and year variables, quantitative variables can prove to be very useful. Using the same example given above :

“Do you want to lose X pounds in X months?”

In this example, pounds is the quantitative variable. You set a benchmark against which your audience can measure their progress (or future progress).

Unexpected winner

Who doesn’t like rooting for the underdog? An unexpected winner is the entity that performs best in an experiment that has the opposite of the expected outcome.

For example, you could compare two popular weight loss methods in your own experiment and publish the unexpected results. Simply reveal the answer in the subject line to entice people to open your email.

Simple tasks

What would you think if we told you that you could lose weight just by sitting in your favorite recliner? It’s a simple task. It’s easy to imagine.

Simple task formula fields tell people they can achieve their goals without much effort.

51 Eye-Catching Email Subject Line Formulas and Examples

Now that we’ve defined some key terms, let’s get into the body of this article. We’ve categorized these compelling email subject line formulas based on the psychological type behind them.

For each formula, we will provide you with three to four examples based on the weight loss theme used above.

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Fear of Missing Out Compelling Email Subject Lines

FOMO. It’s all over Instagram, but it’s real. People don’t like thinking they’re behind the curve or can’t take advantage of something valuable.

You can use FOMO to convince people that you have something they want. This psychological principle is perfect for crafting compelling email subject lines.

What if the result is negative? Here are the solutions

For this formula, introduce the potential negative outcome your reader may experience, then address the pain point by proposing a solution in the body of the email.

• What to do if you fail to lose weight? Here are the solutions.
• What to do if you gain the weight back? Here are the solutions.
• What to do if you’re stuck on a fad diet? Here’s how to fix it.

Are you making any of these (overall theme) mistakes?

A great way to get people to open your emails is to ask questions like this. It inspires FOMO because everyone wants to know if they’re making a mistake that’s not conducive to achieving their goals.

• Are You Making These Weight Loss Mistakes?
• Are You Making These Workout Mistakes?
• Are You Making These Fat-Storing Mistakes?

One day left to get tips on (overall topic) from (name of industry authority)

This subject line combines FOMO with urgency and social proof. You’re evoking a well-known name, describing a benefit, and letting your readers know they only have a limited time to take advantage of the opportunity.

• One day left to learn weight loss secrets from Jenny Craig
• For one day only, get 10% off new Jenny Craig books
• One day left to get tips from Robb Wolf

In one hour, (name of industry authority) will stop helping you

This is very similar to the previous one. Combining urgency with social proof can be very effective.

• In one hour, Chris Powell will no longer be able to help you
• There’s one hour left before Jillian Michaels stops helping you.
• In one hour, Amelia Freer will stop helping you

What if it only took you (years/months) to achieve (positive outcome)?

This is problem-based alternatives. It inspires FOMO and helps the reader start imagining what they would do in this specific situation.

• What if you only had one year to lose those last 50 pounds?
• What would you do if you only had a month to completely overhaul your eating habits?
• If you only had one year to qualify for a marathon, what would you do?

Curiosity-inspired email subject lines

Curiosity always triggers good emotions in your audience. If you can make people curious, you can get them to open your email.

(Target Market)! Here’s How I Got (Positive Outcome)

This will excite your readers because they will think (hopefully correctly) that you have a secret they don’t know about.

• Fad Dieters! This is how I lost 100 pounds!
• Glutton! This is how I beat my late night hunger!
• Weight Loss Failure! Here’s How I Achieved My Weight Loss Goals!

(Overall Theme) The conspiracy is revealed

If you’re going to use this attention-grabbing email subject line, you’d better make sure you’re exposing a real conspiracy. Otherwise, your readers will be disappointed.

• Weight loss conspiracy revealed
• Fad diet conspiracy revealed

The hard truth about (overall topic) or (positive outcome)

Spark curiosity by hinting at a difficult lesson the reader needs to learn about a topic or how to achieve a positive outcome.

• The cruel truth about weight loss
• The Harsh Truth About Counting Macros
• The Harsh Truth About Calorie Deficit

Defend (a controversial topic)

You can also put a positive spin on controversial topics to get people to open your emails more often.

We won’t provide examples here because it would be repeating some of the formula fill-in from before, but make sure you’re responsible for what you say. Don’t use controversial topics to entice people to read your email. They’ll feel deceived.

(Name of industry authority) discusses (controversial topic)

There’s no reason not to use headlines to your advantage. Share what you know about a subject, but write your own editorial on the subject so it comes across in your voice.

• Oprah talks yo-yo dieting
• Jenny Craig Talks Processed Foods
• Jillian Michaels Talks Shakeology

(Overall Topic) Secret (Name of Industry Authority) Almost Taken to the Grave

We’re veering into clickbait here, but if you have something interesting to share, you might also be able to get your audience excited about it. Again, make sure you back up that compelling email subject line with thoughtful, accurate information.

• Jordin Sparks Almost Takes Her Weight Loss Secret to Her Grave

(Industry authority name) was shocked by (trusted information source)

Sometimes industry pundits get into disputes. This is your chance to share the controversy with your readers, and your opportunity to voice your opinion. Tell the story in your own words (and cite your sources). Then provide your own commentary.

• Sophie Gray shocked by Today’s Fitness article
• Joe Cross is shocked by Slim Fast’s claims
• Leslie Jones is shocked by Weight Watchers’ new product

One (overarching theme) book to rule them all

Everyone is looking for the quickest way to get information. That’s why in marketing, we encourage brands to write long, valuable articles to attract traffic . If you can provide readers with everything they need in one place, you’ll become an authoritative, trustworthy source and traffic magnet. You can include this in your email marketing subject lines. In addition, the book also incorporates some pop culture references.

• One weight loss book to rule them all
• One weight loss supplement to rule them all
• One evil exercise to rule them all

Compelling Email Subject Lines

Appealing to yourreaders’ vanity can have a huge impact on your email marketing campaigns. People love learning new ways to make themselves look and feel better, and if you can compliment your readers in some way, you’re ahead of the curve.

(Unexpected winner) looks better because (Controversial topic)

Here, we see unexpected results based on controversy. We want readers to know that people can be successful even when they use strategies that others may disagree with.

We don’t want to share this example because Wednesday prefers to avoid offending anyone . To fill in the blanks, you need some source of data as well as evidence to prove that the results were due to the controversial topic.

(Industry authority name) shares the secrets of (positive results)

This is another great idea. You call up a well-known name and share their secrets to achieve a specific positive outcome.

• Kevin Hart shares his secrets for staying motivated
• Chad Wesley Smith Shares Tips for Improving Your Powerlifting Potential
• Dan Harris shares tips for keeping your mind clear while working out

From (negative outcome) to (positive outcome)

This is a simple but powerful email subject line formula. It shows that you’re going to share someone’s journey from a bad outcome to a great outcome.

• From overweight to healthy and happy
• From resentment and denial to a healthy relationship with food
• From skinny to lean

It’s not your fault that you didn’t achieve (positive outcomes)

We often assume that our failure to reach our goals is due to some variable that is beyond our control. But this is not always the case. For example, you can do a great job of eating healthy and exercising but still not lose weight because of a hormonal imbalance.

Do you know enough to fully understand (overall topic)?

For this formula, we question our readers about how much they know about a particular topic. Many people consider themselves experts after hours of research, but perhaps we can share something that will surprise our readers.

• Do you understand enough to fully comprehend macros?
• Are you educated enough to fully understand calorie counting?
• Do you really understand a calorie deficit?

You can’t accept the truth (of positive outcomes)

This is another fun pop culture reference that ties into a subject that sparks curiosity.

• You can’t accept the truth about weight loss
• The truth about building muscle you can’t accept
• You can’t accept the truth about wearing jeans before becoming a mother

Can you forgive your (overall theme) enemies?

There are at least two sides to every topic. Regardless of your industry or field, there will always be people who disagree with your opinion on how best to achieve a particular goal or solve some problem. Explore this in your email with a subject line that sparks curiosity and empathy.

How does (accidental winner) get (positive outcome) when you don’t get (positive outcome)?

Again, I won’t give an example here so as not to offend anyone, but this is a compelling email subject line that you can use to inspire your readers. If they see an unlikely candidate achieve results, you can reverse engineer success for your audience.

You wouldn’t know (overall theme) if it hit you in the face

We’re walking a delicate line here. You don’t want to outright insult your readers, but you do want to give them a reason to open your email. It’s all about balance. Use a headline like this to grab your reader’s attention, then open the body of the email with empathetic and reassuring copy to balance out the harsh subject line .

Greedy attention grabbing email subject lines

Everyoe gets greedy from time to time. When you see success — in any form — you want it. If you have a chance to get something you want, you’ll probably take it, even if it’s not the most honorable way. These attention-grabbing email subject lines tap into people’s inherent greed .

How it ends (positive outcome)

This is a simple one. This is a great theme if you want to introduce a long-form article or video that provides in-depth information.

• How to Finally Break Through Your Weight Loss Barrier
• How to completely eliminate midnight cravings
• How to Finally Overcome Your Fear of the Gym

The Hidden Secret of (Positive Results)

We love secrets, right? If you can reveal a hidden truth for your readers, they’ll be forever grateful to you, especially when it involves a shortcut to achieving your goals.

• The secret to losing weight without exercise
• The secret to losing weight without dieting
• The Secret to Maintaining Weight Loss

Show me (positive results)!

Again, if you can reference pop culture, that’s fine, but it takes it to another level by stimulating the reader’s greed.

• Tell me the path to successful weight loss!
• Tell me how to beat fatigue!
• Tell me the secret to a low BMI!

Glad to have (positive results)

This email subject line example is one of my favorites . It gives you the opportunity to express gratitude for the things that are going well in your life while also sparking a desire for the same things in your readers.

• It’s so nice to have a healthy body!
• What a joy to have stronger muscles!
• So nice to have more energy!

(Positive results) are waiting for you

This subject line hints that good things are about to happen. You need to provide a truly valuable hint in the body of the email to make this subject line work.

• A healthier body is waiting for you
• Better fitness performance is waiting for you
• Stronger muscles are waiting for you

Pain Point Compelling Email Subject Lines

Now let’s talk about pain points. This always sounds a little cheesy, but pain points are universal. Everyone has them. For example, if you don’t know how to fix an overflowing toilet, your pain points are the plumbing problems you can’t fix on your own.

How to use a trick to allow (unexpected hero) to avoid (negative outcome)

In this topic, you can highlight someone in your industry or field who became an unexpected hero. Share how he or she used a specific strategy to avoid negative outcomes or mistakes.

Most Common (Overall Theme) Mistakes (Target Market) Made!

It’s an old saying, but it’s a valuable one. It also works well as a headline. For this one, make your target market as narrow as possible.

• The most common weight loss mistakes moms make
• The most common dieting mistakes teens make
• The most common workout mistakes runners make

(Name of industry authority) talks about (negative results) of (target market)

This one might seem a little confusing, so let’s break it down.

Start with the negative outcomes for your specific target market. For example, it may be difficult for a mom to lose the baby weight after giving birth. Now, you just need to find an industry authority whose quote you can use to help your target audience avoid these negative outcomes.

(number) The mental illness cause that led you to (negative outcome)

In this case, we point out common mistakes or weaknesses that people make for stupid reasons. Often, it’s just a wake-up call that a big change is needed in the audience.

• 11 Mental Illness Reasons Why You Can’t Lose Weight
• 27 Psychological Reasons You’re Losing Muscle Instead of Fat
• 3 Psychiatric Reasons You’re Putting Off a Diet

No more (negative results)! It ends today!

It’s a funny story. It’s inspiring and uplifting without being too cutesy. You can throw in some tough love, too.

• No more excuses for not working out! End it today!
• No more cheat days! End it today!
• No more weight loss wall! It ends today!

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A well-crafted subject line can mean the difference between whether your email is opened and read, and whether it is ignored or deleted. Here are some reasons why you need an eye -catching subject line: