With any email campaign, you have one goal: get people to open your emails. But data tells us that without a great subject line, you won’t break through the noise and your email ends up just another unopened message in someone’s trash folder. 

Don’t believe me? On a typical workday, an average employee receives around 121 emails in their inbox.

What makes your email stand out?

Rather than go with gut feelings or current best practices, we dive deep into data analytics and answer your biggest questions about how to write better email subject lines.

The Importance of the List

Look at the front page the next time you perform a Google search. You’ll notice a bombardment of ads, featured images, and business listings. It’s getting harder and harder to rank on the first page of the world’s largest search engine without paying to play.

When you add in Facebook, Twitter, and other social media companies regularly updating their algorithm, there is only one place where you have complete control over what your audience sees: your email list.

Keeping that control is essential when growing your digital presence. Your potential audience is already checking their email 5 hours a day which tells us that building your email list is the absolute best way to reach your audience online.

There are many options to build your email subscriber list, but what does research tell us about email subject lines?

What Does the Data Tell Us About Email Subject Lines?

When it comes to writing the best email subject lines, is there a science behind every blurb, or do people write what they believe is the best summation of their message?

As I poured through the pages and pages of data available, all of the analytics point to the same thing: whether we realize it or not, email subject lines have an incredible impact on how people interact with our messages.

Using this information, I’ve put together a data-driven approach to writing better email subject lines and improving open rates (how often someone opens your email).

The Choice to Open Your Email Happens in a Split Second

Adults make 35,000 remotely conscious decisions every day- about 20,000 decisions every hour or one every two seconds. Based on that simple data, we can infer that whether or not someone chooses to read your email happens within seconds.

As a marketer, this information is essential knowledge because we now know that email subject lines have an incredible impact on whether or not your newsletters are opened.

To back up this information, there are two marketing concepts I’d like to introduce: the 12-second rule and the 3-5-7 rule. Both provide clear marketing best practices to keep in mind while developing your email campaigns.

The critical part of the 3-5-7 rule for this article states that you only have 3 seconds to capture someone’s attention with your email subject line.

The concept of the 12-second rule refers to the fact that the average person spends 12 seconds reading an email. More recent data shows that people are spending more time reading emails, but the overall conclusions remain the same: people skim their emails.

How does that affect your email subject lines?

Science and data prove that you have limited time for someone to choose to open your email, so you need to create a subject line that entices readers as quickly as possible.

Something else to have in the back of your mind as you design email campaigns is that research from SuperOffice shows that 45% of subscribers say they are likely to read your email because of the sender. The same survey highlighted that 33% of subscribers opened based on the subject line.

This tells us that if you’ve developed a strong relationship with your subscriber list, it’s more likely that someone will open your email because you sent it versus having the perfect subject line.

What is the Perfect Email Subject Line Length?

The next question you’re probably wondering is, “If my readers are only skimming my subject line, how long should it be?”

Thankfully, there is more than one piece of data to help us out.

In 2015, Return Path looked at emails from over 2 million subscribers to identify trends that might help create better open rates. They found most subject lines were between 41 and 50 characters, but subject lines 61 – 70 characters long had the highest read rate (17%). Read rate reflects how many people opened your email and spent time reading it.

After investigating character subject length from 0-100 words, the result was “actually no correlation between the length of a subject line and its read rate.” But that data only tells part of the story.

Many articles about email marketing best practices tout the importance of having a shorter subject line but need to connect all the potential factors as to why that might be true.

First off, on a desktop screen, you’ll see around 60 characters of your subject line, whereas if you’re on mobile, you’ll only see about 25-30 characters. Bluecore’s 2021 survey concluded that 53% of respondents from all demographics said their smartphone is the primary device in which they check their email.

That data point, in addition to the information related to making decisions, allows us to conclude that shorter email subject lines (25-30 characters) are better if only because most of your subscribers will be reading your emails on their mobile devices.

If you decide to write a subject line longer than 30 characters, that’s fine, but you may alienate your younger audience and those who prefer using their smartphone to their desktop.

Use the Right Keywords to Capture Your Audience’s Attention

Choosing the right length only matters if you know the right words to capture your audience’s attention. A Google search of the most powerful words in marketing provides endless possibilities and phrases without much data to back them up.

Let’s take another look at the 2015 study by Return Path. They’ve compiled an extensive list of the most effective words in your email subject lines and their average read rates.

Email subject lines that include the words “cheapest,” “prettiest,” “download,” and “still time” all presented read rates of over 25%. Each of these words fulfills different roles when speaking to your readers.

For example, “cheapest” and “prettiest” are categorized as benefit words that tell subscribers that if they open the email, they will receive something. A term like “download” is more effective as a command and works well when offering free demos or e-books. “Still time” creates a sense of urgency for readers.

Use our list of the top 10 keywords for your email subject lines as a cheat sheet to increase your readership.

In 2013, Campaign Monitor created an email subject line sample from 3,941,735,015 recipients, from 360,872 campaigns and 11,207 lists. The top performers are labeled “Power Words,” and you’ll notice that three of them are community builders.

Phrases like “we,” “you,” and the receiver’s name all help bridge the gap between customer and company. One of the strongest ways to build raving fans is through creating a community, so it makes sense that these particular words increase open rates.

Avoid Spam Trigger Words

Just as important as choosing the right words, picking the wrong words can cause cataclysmic effects on your campaign and your entire email list.

Invesp compiled a series of studies and identified that 69% of email recipients report emails as spam simply because of the subject line. If someone sends your email to the spam folder, all of your future emails will also be sent there.

Yesware identified two trends that are more likely to drive emails into your subscriber’s spam folders: writing in all capital letters and exclamation marks.

In addition to being a potential trigger for landing in a spam folder, all-caps email subject lines receive a reply 30% less often than those that do not, according to an analysis by Boomerang. 

As for exclamation marks, spammers like to create a sense of urgency, according to a data analyst at Symantec Hosted Services. They do so by adding multiple exclamation points, but most email providers filter these out, so you never see them.

Campaign Monitor and Yesware used analytics to identify hundreds of words that lead to poor open rates and are commonly found in spam folders. You’ll notice a lot of sales terminology on both lists, so be careful when choosing your words while writing your email subject lines.

Speak Directly to Your Customers

Do you want to increase your email open rate? Research performed by Experian identifies that emails with personalization (receiver’s name in the subject line) increase open rates by 26%.

To follow that data, McKinsey reports that “71% percent of consumers expect companies to deliver personalized interactions.” Something else to note is that their analysis revealed that among companies that grow fastest, they drive 40% more of their revenue from personalization.

As creepy as it sounds, Facebook, Amazon, and even our smartphones are always listening or watching to provide targeted ads based on where we live, what we like, and who we are. At this point, we’ve gotten used to it, so there’s now a built-in expectation that online experiences are personalized to their tastes.

Those personalization expectations also include email subject lines.

A Bluehornet survey highlights that consumers expect retailers to use information about previous purchases, profile interests, and birthdays when sending out emails.

While all of that information is beneficial when writing and designing email campaigns, 64% of marketers use names as their primary form of personalization in email subject lines.

As Dale Carnegie once said, “A person’s name is to him, or her is the sweetest and most important sound in any language.” Use that to your advantage during your email marketing campaign by directly addressing your customers in email subject lines. The data backs up Carnegie’s beliefs as subject line personalization leads to increases in email open rates and higher consumer satisfaction.

Create a Sense of Urgency

Have you ever experienced FOMO (the fear of missing out)? FOMO “refers to the feeling or perception that others are having more fun, living better lives, or experiencing better things than you are.”

To understand how this affects marketing and email subject lines, we must consider the psychology around FOMO.

Studies indicate that 70% of all adults in developed countries suffer from FOMO. By creating a feeling of FOMO in your email subject lines, you’re developing a sense of urgency.

If you look in your inbox, you’ve probably seen this tactic used multiple times: “Only a few seats left,” “Last Day of Sale,” or “2 rooms left for this date.” Ignoring whether or not these subject lines are 100% factual, you are incentivized to open up these emails because our mind tells us we don’t want to be left behind. An Expedia email study found that emails with “tomorrow” in the subject line were opened 10% more often than those without.

Words such as “urgent” and “breaking” perform best when trying to create a sense of urgency in an email subject line.

Leverage your audience’s desire to feel included by writing email subject lines that create a sense of urgency.

Be Clear

The last and most important insight from the data surrounding email subject lines is that if you want your emails to be opened, you must be clear in what you write.

An Aweber case study republished by The Marketing Sherpa identified that clear subject lines produced 541% more responses across all channels. That number is staggering, but it makes sense considering the circumstances.

Think about it from this point of view: the receiver already signed up for your email content, so you know they like your brand. Rather than be over-creative and vague, your subject lines should be straightforward, clear, and engaging.

The Loop Marketing Wants to Help Your Email Campaigns Soar

Data proves that minor tweaks to your subject lines increase the number of people who open your email. Our digital marketing team specializes in creating engaging email campaigns that not only raise awareness but increase the number of business leads.

Want to see more of The Loop Marketing’s award-winning work? Read our case study on how one piece of content grew web traffic by 700%.

author avatar
Garrett Carlson
Garrett Carlson is the Content Manager at The Loop Marketing. A former creative writing teacher and graduate of the Johns Hopkins Masters in Nonfiction Writing program, Garrett has spent his entire professional career working on putting together the best words, in the best order, to create the best sentences. In 2019, Garrett started his own content website dedicated to improving men’s mental health, advocating for positive male friendships and self-care. Through this experience, Garrett brings expertise in developing Search Engine Optimization, building engaged online communities through the written word and understanding multimedia content (podcasts, webinars, group building) to The Loop Marketing and their clients. Garrett spends most of his free time with his wife, two cats, (Jay Catsby and Daisy Bucaten), and Icelandic Sheepdog Orla while recreating scenes from the Fast and the Furious, and dreaming about all things Buffalo-food.