How to Write a Marketing Subject Line best practice?

Boost Inbox Logo Mia Anderson
April 25, 2024
Marketing Subject Line

In the digital age, where inboxes are flooded with emails, crafting an effective subject line is crucial for capturing the attention of your audience. A well-crafted subject line can significantly impact the open rates and success of your email marketing campaigns. In this comprehensive guide, we will delve into the intricacies of writing compelling subject lines that resonate with your audience and drive engagement.

Use Actionable Language

The foundation of a compelling subject line lies in its ability to prompt action from the recipient. Utilizing actionable language encourages readers to take the desired next step, whether it's opening the email, clicking on a link, or making a purchase. Words such as "Discover," "Grab," "Unlock," and "Explore" instill a sense of urgency and compel the recipient to engage with the email content. For example, a subject line like "Unlock Exclusive Deals Today!" prompts the reader to open the email to learn more about the offers available.

Personalize When Possible

In today's hyper-personalized marketing landscape, generic subject lines are often overlooked in favor of personalized ones. Incorporating the recipient's name or other relevant personalization elements can significantly increase open rates and foster a sense of connection with the brand. Personalization goes beyond just addressing the recipient by name; it involves tailoring the subject line to align with the recipient's interests, preferences, and past interactions with the brand. For instance, a subject line such as "Sarah, Your Exclusive Birthday Gift Awaits!" not only captures attention but also makes the recipient feel valued and special.

Prioritize Clarity, and Then Think About “Catchiness”

While creativity is essential in crafting subject lines that stand out, clarity should never be sacrificed for the sake of cleverness. A clear and concise subject line effectively communicates the purpose of the email and sets clear expectations for the recipient. Avoid cryptic or overly ambiguous subject lines that leave the recipient guessing about the content of the email. Instead, focus on clarity first and then infuse creativity to make the subject line memorable and engaging. For example, a subject line like "Your Weekly Newsletter: Stay Updated with the Latest Trends" clearly communicates the content of the email while also piquing curiosity.

Align Your Subject Line Copy and Email Copy

Consistency is key when it comes to email marketing. Your subject line should seamlessly align with the content of the email to ensure a cohesive and coherent user experience. Misleading subject lines that promise one thing but deliver another can erode trust and credibility with your audience. Make sure that the subject line accurately reflects the main message or offer presented in the email body. This alignment not only enhances the overall user experience but also increases the likelihood of conversions. For instance, if the email promotes a limited-time sale, the subject line should clearly convey this offer to entice recipients to open the email and take advantage of the discount.

Use Emojis

Emojis have become a ubiquitous part of digital communication and can add personality and visual appeal to your subject lines. When used judiciously, emojis can help your emails stand out in a crowded inbox and convey emotions or messages more effectively. However, it's essential to use emojis that are relevant to your brand and resonate with your target audience. Conduct A/B testing to determine which emojis resonate best with your audience and drive higher engagement.

Test Multiple Subject Lines

A/B testing, also known as split testing, is a powerful strategy for optimizing your email subject lines and maximizing engagement. By testing different variations of your subject line with a subset of your audience, you can gather valuable data on what resonates best with your subscribers. Experiment with different wording, personalization elements, emojis, and formatting to identify the most effective subject lines for your campaigns. Continuously monitor and analyze the results of your A/B tests to refine your subject line strategies and improve performance over time. Remember that what works for one audience may not necessarily work for another, so ongoing testing is essential for staying relevant and impactful.


Crafting compelling subject lines is both an art and a science. By incorporating actionable language, personalization, clarity, alignment, emojis, and A/B testing into your subject line strategy, you can increase the effectiveness of your email marketing campaigns and drive higher engagement and conversions. Keep experimenting, analyzing results, and refining your approach to ensure that your subject lines continue to resonate with your audience and deliver results for your business.

What to read next

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The warmup process duration may vary depending on your email volume, but it typically ranges from a few days to a couple of weeks.

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