The average email inbox is often littered with numerous promotional emails, making it challenging to stand out and earn a click from your lead.
What can you do to grab your reader’s attention? Write a perfect email subject line.
It’s the first thing your audience sees and often the deciding factor between “open” and “delete.” So, how do you create one that converts?
Let’s go over the essentials:
• Why Good Subject Lines Matter
• 8 Email Subject Line Best Practices
• 5 Common Mistakes To Avoid
• The Importance of Email A/B Testing
Why Good Subject Lines Matter
A good subject line matters because it makes the first impression of your email.
People often decide whether or not to open or delete an email based on the subject line alone. In a 2021 survey, over 1/3 of respondents filtered their marketing emails for deletion by scanning the subject line.
Imagine receiving two sales emails:
• Exclusive Offer: 40% Off Today Only!
• Sale Today
The first line is urgent and specific, communicating something valuable to the receiver, while the other one lacks interest and appeal.
A good subject line allows your email to stand out in crowded inboxes, increase your open rates and boost conversion rates, leading to better results for your email marketing campaigns.
8 Tips and Best Practices for Writing Effective Subject Lines
Subject lines are more than just a text field in your email program. What you say and how you say it can affect your email recipient’s reaction to your marketing message.
Here are eight email subject line best practices for email marketing tactics that work:
1. Leverage Personalization
Personalization makes emails feel tailored, boosting their relevance in the recipient’s inbox.
Data shows that most consumers worldwide will likely stop supporting a brand if it does not personalize the customer experience.
Incorporate details like the person’s name, location or a previous activity in the subject line to establish a personal connection.
Pair personalized email subject lines with something valuable, like a discount or free resource, for better results.
2. Create a Sense of Urgency
Urgency drives action. Words like “now,” “today” and “ends soon” signify limited-time offers, which motivate email leads to act immediately, boosting your conversion rate.
There’s this phenomenon of FOMO (fear of missing out). Using urgency in your subject lines taps into this instinct.
When coupled with a valuable product or a great deal, you increase your open and conversion rates. Try embedding a countdown timer in the email body to complement your subject line.
3. Incorporate Power Words
Power words evoke interest and emotional responses from your audience. Words like “exclusive,” “proven” and “success” build intrigue and promise value to your audience, encouraging them to open the email.
These words excite your audience and encourage them to perceive your message as special, boosting engagement and open rates.
When leveraging power words, opt for more specific terms to stand out. For example, “exclusive early access” sounds more promising than “amazing deals.”
4. Be Descriptive Yet Concise
Subject lines should be scannable. While you can fit quite a few words in there, most readers will ignore a long-winded email subject line.
Your subject line should convey a clear message while keeping the word count minimal. A mix of specificity and brevity ensures effectiveness.
This subject line provides enough detail to intrigue the recipient and offer something of value without overwhelming or confusing them. Couple this approach with engaging preview text to give more context and support your subject line.
5. Use Numbers
Numbers create structure, communicate a concrete concept and draw attention. They make subject lines more scannable and allow recipients to immediately understand the content of your email.
Lists are naturally engaging, offering quick and easily digestible content for busy readers. Try combining numbers with power words or a benefit to maximize the impact of your email subject line.
6. Consider Emojis
Emojis might seem informal, but under the right circumstances, they can be engaging and allow your email to stand out in crowded inboxes.
However, make sure the emojis you use align with your brand, email list and message. Irrelevant or overused emojis can hurt your credibility.
Emojis catch the eye, making the subject line distinctive without overly complicating the text. The example above uses gift box emojis, which are on theme with the text about Christmas gifts and Etsy’s reputation as a marketplace for gifts and unique finds.
7. Maximize All Available Space
Your subject line is crucial to engaging your audience, but it isn’t the only element you can utilize.
Each email subject line comes with preview text, which you can also customize. These two elements allow you to create a cohesive message that prepares and pushes the recipient to open it.
Take the example above. The subject line offering a discount is reinforced by the preview text “Make 2024 your year,” an encouraging line that communicates positivity and enthusiasm.
8. Use a Familiar Sender Name
Most businesses use their brand name to send marketing emails, and there’s nothing necessarily wrong with that. However, using a person’s name as the sender humanizes your brand and brings you closer to your audience.
People are more likely to open emails from an actual human rather than a corporate brand name. This practice encourages familiarity and closeness between you and your audience, increasing trust and reducing skepticism.
5 Common Mistakes To Avoid
Email subject lines can be short, but crafting them takes thought and strategy. Here are some common mistakes to avoid:
1. Sending From “no-reply” Accounts
Using no-reply as a sender address can sometimes be the default for email marketing or outbound campaigns. However, it feels impersonal and discourages engagement. It creates a one-way relationship, leaving email leads feeling disconnected or ignored.
Most recipients feel valued when they have the option to respond if needed. A real sender name and an email address that accepts replies fosters trust and credibility.
2. Being Too Generic
Generic subject lines like “December Update” or “Monthly Newsletter” don’t really say anything about you or your brand. They lack specificity and will likely be overlooked in crowded mailboxes.
Your subject line should communicate the contents of your marketing or sales email, grabbing people’s attention and conveying clear value.
3. Misleading Your Audience
Clickbait is out. Subject lines that overpromise or use misleading marketing tactics to boost click rates damage trust.
For example, promising something free when it’s conditional or requires a fee can frustrate your prospects. This frustration can then lead to higher unsubscribe rates and damage your reputation.
4. Being Too Pushy or Aggressive
Aggressive sales talk or pushy marketing tactics can overwhelm or annoy your prospects. Examples include pushy language, excessive capitalization or too many exclamation points and emojis.
Take this subject line: ⚠️⚠️⚠️ ACT NOW!! LIMITED TIME ONLY! ⚠️⚠️⚠️
While the example above might seem urgent, it can be too aggressive and spammy. This approach can often alienate and turn off your audience instead of converting them.
5. Using Spammy Words or Phrases
Email platforms often have a built-in spam filter to protect users from scams and malicious actors.
Words and phrases like “free,” “$$$” and “fast cash” are examples of spam trigger words that will likely land your email in the spam folder. If you’re not careful, your emails could get tagged as spam, ending up unseen and unopened.
The Importance of Email A/B Testing
You can put a lot of effort into crafting your email subject lines. However, not every attempt will become successful, hence the necessity of A/B testing.
What Is Email A/B Testing?
A/B testing is a marketing process that involves testing multiple campaign versions to see which performs the best.
In email marketing, you can test different components of your email, from your subject line, content, graphics, call-to-action (CTA) buttons and many more. The winning subject line (or your chosen component) then gets sent to the rest of your email list.
A/B testing allows you to refine your subject lines and overall email campaign, boosting click rates and conversions.
3 Best Practices for Email A/B Testing
Effective A/B testing requires careful planning and execution. Follow these best practices to gain valuable insights that improve your campaign implementation:
1. Identify Specific Goals
Before beginning your campaign tests, define what you want to achieve or measure. Focus on measurable outcomes that align with your campaign objectives.
In the case of email subject lines, you may aim to increase open rates. Clear, realistic goals allow you to effectively focus your efforts and measure success.
2. Set Your Control Variables
Test only one element at a time while keeping other factors, or your control group, consistent. This practice ensures that the differences in your tests are due to the tested variable. It allows you to pinpoint the factors that affect your campaign performance more effectively.
3. Define Your Audience
Select the right audience from your email list based on existing segments or characteristics that match your marketing goal. Keep each group roughly around the same size for better comparisons.
For example, if you’re testing the effectiveness of onboarding emails, focus on users who have recently signed up for your newsletter or product trial.
Elevate Your Email Campaigns With Thrive Internet Marketing Agency
With some well-crafted, engaging and attention-grabbing email subject lines on your sleeve, you’re well on your way to sending powerful emails that audiences can’t help but open.
If you need more help with the rest of your email marketing campaign, consider working with our experts at Thrive. Our email marketing professionals plan, launch and optimize full-scale campaigns that drive clicks and conversions.
In one success story, Thrive launched automated emails that captured over $42,000 in sales, and our newly created templates for the weekly email campaigns generated nearly $20,000 in revenue.
Let’s work together – call us today.
Frequently Asked Questions (FAQs) About Writing Effective Email Subject Lines
WHAT MAKES A GOOD EMAIL SUBJECT LINE?
A strong email subject line is clear, concise and relevant to the recipient. It grabs attention with specificity or emotion — often through personalization, power words or a sense of urgency — while accurately reflecting the content of your email.
WHY ARE EMAIL SUBJECT LINES SO IMPORTANT?
The subject line is your email’s first impression. Most recipients decide whether to open or delete an email based on it alone. A well-written subject line helps your message stand out in crowded inboxes, increases open rates and ultimately improves conversions.
HOW LONG SHOULD AN EMAIL SUBJECT LINE BE?
Keep your subject line short and scannable — ideally under 50 characters or about six to eight words. This ensures your message displays fully on mobile devices and catches attention quickly without overwhelming readers.
WHAT ARE SOME COMMON EMAIL SUBJECT LINE MISTAKES TO AVOID?
Avoid using “no-reply” addresses, clickbait or misleading statements, excessive punctuation or all caps and spam-trigger words like “free,” “$$$” or “fast cash.” These tactics can damage trust or send your emails straight to spam folders.
DO EMOJIS WORK IN EMAIL SUBJECT LINES?
Yes — when used thoughtfully. Emojis can make subject lines stand out visually, but they should fit your brand tone and audience. Overuse or irrelevant emojis can make emails seem unprofessional or spammy.
HOW CAN I USE A/B TESTING TO IMPROVE MY EMAIL SUBJECT LINES?
A/B testing lets you compare two or more versions of your subject lines to see which performs best. Test one variable at a time — like word choice, personalization or tone — and track metrics such as open rate to identify what resonates most with your audience.
SHOULD I PERSONALIZE EVERY SUBJECT LINE?
Whenever possible, yes. Adding a recipient’s name, location or relevant behavior makes your message feel tailored and builds a stronger connection. Just make sure your personalization feels natural and adds value to the email.
HOW CAN THRIVE HELP IMPROVE MY EMAIL MARKETING RESULTS?
Thrive’s email marketing campaign experts plan, test and optimize data-driven campaigns that boost engagement and conversions. From compelling subject lines to full-scale automation and reporting, we help businesses turn emails into powerful relationship-building tools.
