Subject line ideas to boost email open rates

Wanting to increase your rate of email opening? Marketing experts who achieve high open rates use what are proven principles of psychology to write eye-catching subject lines for emails that grab the recipient’s attention and thus prompt them to read an email. With this guide, we will share 101 examples of the best email subject lines that subscribers can’t resist.

Why do you need subject lines that work?

Some 47% of email recipients will open an email based on subject line alone. Simultaneously, 68% of recipients report email as being spam based on the subject line.

Putting it simply: subject lines have the ability to be make or break for an email marketing campaign.
The best way of writing an email subject line that leads to the email being opened (instead of sent to spam) is by appealing to basic human nature and principles of psychology.

Without further ado, here’s 40 of the best examples of email marketing subject lines, and the time and tested principles which mean they work...

Fear of missing out

One principle of psychology which is impossible for people to resist is the fear of missing out. This fear can be put to good use in subject lines simply be adding an element of scarceness (limited availability) or importance (limited time).
Subject lines that include words implying time sensitivity like ‘alert’, ‘breaking’, ‘urgent’ or ‘important’ –are all proven to increase the rate of emails being opened.

Here are some good example email subject lines that make use of the fear of missing out...

1. Kroger: “Uh-oh, your prescription is about to expire.”
2. Spirit Airlines: “You are missing out on air points.”
3. Koozai: “URGENT! You have only ONE DAY to watch this…”
4. Big Bite Submarines: “John, earn double points only for today.”

Curiosity

Human beings naturally desire closure – we do not enjoy the unknown. You can use this desire for closure by making a subject line open-ended peaking the curiosity of subscribers, and giving them some kind of cliffhanger that is only concluded by opening the email.

Subscribers can be made curious through the asking of a question (and by providing the answer to it in the email), the promise of something interesting (like a surprise gift), or by simply saying something sounding strange or unusual.
Here’s some examples of curiosity inducing subject lines...

1. Red Door Spa: “Do not open this email.”
2. BuzzFeed: “What do they eat in prison?”
3. Starbucks: “Your last chance to discover what this mystery email is about.”
4. Wallmart: “A surprise gift for you!”

Humor

If a subject line makes subscribers laugh, they will feel compelled to open it.
Composing a humorous subject line requires some creativity and thought, but can really pay off in terms of rates of opening.

Here’s some amusing email subject lines to make subscribers smile...

1. Boston Winery: “Where to drink wine right now” (Sent at 6am on a Thursday.)
2. Groupon: “Deals we are proud of (unlike our niece, Carol)”
3. Travelocity: “Need a day at a spa resort? Just follow your nose to paradise…”
4. Baby Bump: “Yes, I am pregnant. Now stop staring at my belly.”

Vanity

Everyone has a vain streak. We all like to be liked and accepted by others.
It is for that reason some of the cleverest subject lines appeal to vanity to get people to open an email.
Here are some good examples of email subject lines that appeal to people’s sense of vanity...

1. Levis: “Don’t wear last season’s style.”
2. Bloomingdales: “Gift inspiration for the discerning woman.”
3. L’Oréal: “Age-defying beauty tips.”
4. GAP: “Clothing lines favored by celebs.”

Greed

It can be really tough for people to pass up a good deal, even if they don’t really need the item. That is why special offers, discounts and sales work really well in subject lines.

Caution is needed when offering big discounts – the higher the savings are, the less reliable the effect on open rates (likely due to the fact consumers do not really believe large discounts are legit).

However, you usually should expect to see a hike in click rates every time you offer a discount in an email subject line.
Here’s some good email subject line that are likely to hit a subscriber’s “greed” button...

1. GAP: “Meet your latest jeans.”
2. GAP: “30% off your favorites.”
3. Guess: “Two for two.”
4. Ralph Lauren: “A touch of luxury at a great price”

Laziness or sloth

A common trait shared by all humans is sloth, or the tendency to shirk work. Even those who are not usually lazy still prefer to find the easiest way of doing something possible.

By showing subscribers an easy way to achieve what they want with a shortcut, or useful resources that can save them time and energy they are more likely to open an email. (These useful subject lines are also ideal for lead nurturing).
Here are a few good examples of email subject lines that appeal to people’s laziness…

1. MailChimp.com: “25-point checklist for the creation of the ultimate optin form.”
2. Digital Marketer: “Feel free to steal these email templates.”
3. MailChimp.com: “A native ad in less than 60 minutes.”
4. Digital Marketer: “101 ideas for blog posts.”

Pain Points

If you want to understand your buyers’ personas, you should understand their greatest pain points. Utilize those pain points to make subscribers open emails by solving the specific problem for them.

Here are a few examples of subject lines for emails highlighting a subscriber’s pain points and offering a solution…

1. Domino’s Pizza: “Unexpected guests? Feed them the easy way.”
2. IKEA: “Where should I put all these toys?”
3. IKEA: “Free up more kitchen bench space with these easy fixes.””
4. HP: “Don’t waste money on ink.”

Retargeting

Retargeting emails are a type of email sent to subscribers after they have failed to complete a course of action or a step that needed to take place for your sales funnel to be completed (for example they abandon their cart, or they fail to purchase the product or service after a free trial). The purpose of these emails is to bring subscribers back into the sales process.

Effective retargeting subject lines can be written by overcoming any objections the subscriber may have, by offering a carrot to complete the deal, or by warning them of consequences if they fail to take action.
Here are some ideal examples of retargeting subject lines for emails…

1. Bonobos.com: “Hey, forget to order something? Here’s 30% off.”
2. Target: “The price has been slashed for something in your cart.”
3. Unroll.Me: “We are deleting your account.”
4. Vivino: “We don’t want to give up on you!”

Personal

A study conducted by Experian Marketing Services in 2015 showed personalized email subject lines that included a name led to an average boost in opening rates of 29.3% across all industries.

However including your subscriber’s name is not the only way to personalize your subject lines. You can try to use more casual language, use copy that implies friendship or familiarity or share something personal.
Just try not to play “tricks” on subscribers by allowing them to think you’re actually a friend.
Here’s some examples of attention grabbing personal email subject lines…

1. Guess: “Susan, check out these looks hand-picked for you.”
2. Bonnie Fahy: “Susan, have you forgotten us?”
3. Brooklinen: “Chocolate or vanilla?”
4. Revolution Tea: “Thanks for your help.”

Straightforward

When you aren’t sure, a simple and straightforward subject line is the way to go. Despite what you may think, these supposedly “boring” subject lines actually convert quite well.

To make this work it is crucial to provide some value in all emails you send. Do not send an email if you do not have anything important to say: consistently ensure your campaigns are of value. Do this, and your subscribers will open your emails regardless of the subject line.

Here’s some examples of no-nonsense email subject lines…

1. Al Franken: “You’re right, this is about fundraising.”
2. AYR: “Our best winter coat ever.”
   …and then there are so-called “boring” subject lines. However they perform well with open rates of between 60 and 87%…
3. “[Company Name] sales and marketing newsletter.”
4. “[Company Name] June 2016 news bulletin!”

Final Tips

Before choosing a subject line at random, keep these tips in mind for the highest possible open rates.

• The majority of people now open emails on mobile.

Whatever strategy you use, make sure you optimize your subject line for mobile users.

• Originality is Key

The thing is your subscribers can get easily bored. If are wanting to engage both first-time openers and long-term subscribers, you will need to keep things fresh consistently.

• Try Out Emojis

According to an Experian report, the use of emojis in subject lines can lead to an increase in open rates by up to 45%.

Here are the 15 most-used emojis in subject lines.

They are not necessarily the “best”, but they are the most popular. Exercise some creativity with emojis and emoji combinations in your email subject lines.