Email Subject Lines: 10 Best Practices to Increase Open Rates

In email marketing, a crafty, engaging subject line is your key to catching people’s attention. This line is the first impression you’ll make on readers; in many cases, it’s more important than the actual body of your email, because all the effort you put into creating an excellent email doesn’t matter if it goes unopened in the first place. 

The goal is to hook readers so they click on the subject line and open the email. The more times your email is opened, the better the open rate–which is the number of people who actually opened your email out of the total number of subscribers you sent it to.

How can you create eye-catching, successful subject lines and avoid coming across as potential spam? Incorporate these best practices into your subject lines to make them stand out and ultimately increase your open rates. 

Email Subject Line Best Practices

1.) Understand Your Audience

Like many other aspects of digital marketing, it’s essential to be familiar with your audience as you create email subject lines. This familiarity will set your tone and help you cater to specific interests. It’s possible to use funny or shocking email subject lines (ones that use puns or make a jolting statement), but these run a lot of risks and you have to know whether your audience will be receptive to them. 

You can also personalize subject lines by using an individual’s first name. Or, utilize retargeting to provide a specialized offer on items that a customer may have looked at or purchased previously. Take time to understand what style, language, and offers your audience will find attractive.

Examples: 

• Mary, thanks for participating
• More art classes offered in your area 

2.) Keep It Short and Direct

People are busy. Your message should be short and sweet, providing as much information as possible. Keep in mind that most subject lines need to be 50 characters or less, and ones that have 4-7 words have a higher open rate. Even subject lines with just a few words can attract readers. 

Examples: 

• How are things going?
• Top suggestions for this week 

3.) Use Punctuation and Emojis Sparingly

Punctuation and emojis are great tools to make your subject line stand out and break up the normal text.

However, use them sparingly; excessive emojis may alienate some readers, and make sure the ones you use truly are relevant to your subject or sale. Exclamation points can help you emphasize your message, but more than one or two can also be off-putting. 

In fact, MailChimp conducted a study that found 3 punctuation marks and 1 emoji is the general limit for a subject line.

Examples: 

• Remember–sale ends today!! 
• Reasons we  St. Patrick’s Day 

4.) Include Numbers and Lists

There is a reason why “Top 10” blogs are so popular. Listing content helps break it into smaller and more readable chunks, promising an easy and quick read. It also generates curiosity, as people want to see what the #1 thing is. This trick can work in your subject line. 

Another way to include numbers in your subject line is to use a statistic. This additionally provides insight and straightforward information. 

Examples: 

• The easiest 7 dinners that kids love 
• 70% of people buy their gifts last minute 
• Our top 10 lipsticks for fall 

5.) Take Advantage of FOMO

The fear of missing out is very common. A great marketing strategy is to tap into this fear and other scarcity tactics such as putting a time limit on a sale; this provides incentive and a sense of urgency. Emphasize this urgency in your subject line with numbers and exclamation points. 

Examples: 

• 50% off jeans. Today only!
• 10 spots left, reserve your place now. 
• Free shipping! (48-hour offer)

6.) Tap Into Positive Emotions 

You don’t have to necessarily make your readers fearful in order to get them to open your email–there are plenty of positive incentives to tap into as well. For example, people enjoy being on top of the latest fashions and trends. An email promising a sneak-peek into something that’s up and coming can get a high open-rate. 

Or, offer great incentives that subscribers can’t pass up. This might be exclusive content, the chance to win something, or a free trial. People are likely to open the email just to get more information on the offer. 

Examples: 

• An exclusive look at our new features 
• Our predictions for trends in 2021

7.) Ask A Question

Posing a question immediately engages your subscribers. Rather than simply stating something, you open the opportunity for conversation. Open-ended questions that don’t simply have yes-or-no answers pique a customer’s curiosity. 

Examples: 

• How’s your new laptop? 
• How much chocolate is too much? 
• What’s next for remote workers? 

8.) Include a CTA 

A CTA (call to action) is another marketing strategy you can use in your email subject line. These are quick, simple phrases that tell the reader the action they should take. They express urgency and are very direct. Following with exclamation points enhances the impact (but remember to use only one or two). 

Examples: 

• New expert webinar. Reserve your spot now! 
• Subscribe now for daily beauty tips

9.) Go Local 

By using location-specific language, you show subscribers that you’ve done your research; you’re familiar with their vicinity and have information or offers that apply to their unique circumstances. It’s an extra step to personalization that can do the trick–many people open emails like this just because they are interested in seeing what’s happening in their local area. 

Examples: 

• The best new restaurants in Los Angeles 
• Join us at Millennium Park in Chicago  

10.) Test Your Subject Lines 

One of the best ways to learn if your subject line is successful is to run an A/B testing campaign. A/B testing is a simple experiment that compares two versions of one variable and determines which version is more effective, depending on a subject’s response. 

In this case, your experiment will involve creating two emails that are similar in every way except for the subject line. Send them to randomly selected subscribers, then observe which email gets opened the most. This tells you what subject line appeals to your readers and how even a small difference can make a big impact on open rates. 

The more you run A/B testing on your subject lines, the more you’ll begin to understand your audience and their interests or preferences. It’s a simple yet effective way to familiarize yourself with subscribers and create successful email campaigns. 

How Increasing Open Rates Helps Your Business

Generally, the higher your open rate, the bigger your outreach. In combination with other marketing strategies and metrics, this helps to enhance sales. Open rates are an essential metric because they are a good indication of your engagement with your subscribers. If your open rates are very low, you may be sending too many emails or not doing enough to encourage readers to open them. 

A great technique to boost open rates is to create great email subject lines that connect with your subscribers’ interests and hook them into finding out more. Create a few experimental subject lines by incorporating the best practices listed above. Run A/B testing to see which ones get the most open rates, then base your email subject lines on what’s successful. 

Need help developing your company’s email marketing strategy? Contact the experts at Infinity Marketing Group.

J.C. Granger is the CEO of Infinity Marketing Group. Infinity Marketing Group is an inbound marketing agency headquartered in Denver, Colorado that specializes in helping SaaS companies achieve their lead generation goals.

Connect with J.C. on LinkedIn and download this free eBook, "The 3 Essentials of Inbound Marketing"