The Complete Guide to Write Astonishing Email Subjects

The Complete Guide to Write Astonishing Email Subjects

Julie Cauville

Julie Cauville

April 11, 2023

Your email subject line is like the headline of an article.

It's the first thing your recipients see, and it determines whether they will open your email or not. In fact, 8 out of 10 people will read the subject line, while only 2 of 10 will click through.

So how do you write email subjects that convert? This article presents a five-step process based on a study to help you create perfect email subjects.

Step #1: Use Specific Numbers and Data in Your Subject Line

Incorporating specific numbers and data into your email subject lines can significantly improve their appeal and effectiveness.

Research studies have shown that subject lines featuring numbers tend to generate more opens and engagement. Numbers act as "brain candy" because our brains are naturally drawn to them.

To leverage the power of numbers in your subject lines, consider the following best practices:

  • Use small numbers: Smaller numbers are easier to process and understand.

For example, instead of writing "100 Tips for Saving Money," consider using "7 Essential Money-Saving Tips" as your subject line. The smaller number makes the content feel more accessible and less overwhelming.

  • Use odd numbers: Studies show that odd numbers are perceived as more authentic than even numbers. This is because odd numbers help people digest and recall information more easily.

For instance, you might choose "5 Proven Strategies to Boost Your Email Open Rates" over "4 Proven Strategies to Boost Your Email Open Rates."

Examples of subject lines with specific numbers and data:

  • "7 Quick Tips to Increase Your Productivity Today"
  • "9 Essential Steps to Launch Your Online Business"
  • "11 Surprising Facts About Social Media Marketing You Need to Know"
  • "5 Secrets to Mastering Remote Work-Life Balance"

Step #2: Use a Unique Rationale in Your Subject Line

A rationale is an underlying reason why something should be done.

When crafting your email subject lines, it's essential to include a unique rationale that convinces recipients to click and engage with your content.

By doing so, you make your email stand out and give readers a clear reason to explore the content further.

Here are some examples of rationales you can include in your subject lines:

  • Lessons
  • Tips
  • Tricks
  • Ideas
  • Ways
  • Principles
  • Facts
  • Secrets
  • Strategies
  • Reasons

Examples of subject lines with unique rationales:

  • "5 Expert Tips for Writing Better Email Subject Lines"
  • "The Top 7 Lessons I Learned as a First-Time Entrepreneur"
  • "8 Effective Strategies for Boosting Your Social Media Engagement"
  • "10 Surprising Facts About Email Marketing That Will Change the Way You Think"
  • "6 Proven Secrets to Maximize Your Landing Page Conversion Rates"

To create email subject lines that incorporate unique rationales, follow these steps:

  1. Identify your target audience's needs: Understand the problems, desires, and preferences of your target audience to create subject lines that resonate with them.
  2. Select a suitable rationale: Choose a rationale that aligns with your audience's needs and the content you are sharing. Ensure that it adds value and relevance to your email.
  3. Craft a compelling subject line: Combine the selected rationale with other elements, such as specific numbers and emotional words, to create an enticing subject line that encourages readers to open your email.

Step #3: Call for Attention in Your Subject Line

The primary purpose of your email subject line is to grab your recipient's attention and entice them to open and read your email. Considering the average person's attention span falls between 12 and 8 seconds, it's crucial to make an instant impact with your subject line.

To capture your readers' attention, you can use the "4 Us" method:

1. Make your subject line Unique: Ensure your subject line stands out from the crowd by making it original and interesting. Test your subject line's uniqueness by searching for it on Google with double quotation marks. If it doesn't appear elsewhere, you're on the right track.

2. Be Ultra-specific: Your prospects want answers to their questions. The more precise you can be, the more authority you'll command, and the easier it'll be to build a strong connection with your audience. To achieve this, know your audience, define your hooks, and create subject lines that address their needs.

Examples of ultra-specific subject lines:

  • "3 Simple Steps to Write a Small Business Plan for Beginners"
  • "Top 10 Small Business Plan Templates That Succeeded"
  • "Learn How to Write a Small Business Plan From Scratch"
  • "Step-by-Step Process for Writing a Small Business Plan in 30 Minutes"

3. Convey a sense of Urgency/scarcity: Creating a sense of urgency or scarcity in your subject line can encourage readers to open your email because they don't want to miss out. Make sure your subject line conveys the value they'll receive by opening your email immediately.

4. Provide something Useful: Ensure your subject line and email content are valuable and relevant to your audience. This includes sharing practical tips, helpful advice, and informative insights. To enhance the usefulness of your content, include data, screenshots, and in-depth information to support your points.

Application of step #3:

1 Write easily understandable subject lines:

Instead of trying to sound clever or educated, focus on simplifying complex topics and using relatable language.


  • ❌ "12 Meticulous Savings Tips for the Financial Amateur"
  • ✅ "12 Effective Saving Tips for Those Who Want Extra Cash"

2️ Use interesting adjectives in your subject lines:

Adjectives can evoke emotions and keep your audience engaged.

Examples of interesting adjectives:

  • Fun
  • Painstaking
  • Free
  • Strange
  • Incredible
  • Effortless
  • Absolute
  • Essential

3️ Flag the reader in your subject lines:

Address your readers as "you" to create a personal connection and make them feel included in the conversation.


  • "For Clickbank Affiliates Only: Double Your Affiliate Commission in 15 Minutes a Day"
  • "WordPress Fashion Bloggers: 4 Ways to Secure Your Blog Against Hackers"
  • "Struggling Bloggers: Create an Endless Stream of Content Ideas With This 1 Website"

4️⃣- Use emotional words (power words) in your subject lines:

Incorporate power words to evoke strong emotions and make your subject lines more impactful.

Remember to use power words naturally to avoid sounding forced or getting penalized by email service providers for "keyword-bombing."

By applying these techniques, you can create attention-grabbing email subject lines that encourage readers to open your emails and engage with your content.

Step #4: Deliver Value in Your Email Content

Your email content is crucial in building trust and maintaining a strong relationship with your subscribers. To ensure your content delivers value, follow these guidelines:

  1. Keep it relevant and focused: Ensure that your email content matches the expectations you set in the subject line. If your subject line promises tips on writing a small business plan, your email should deliver on that promise. A study by Chadwick Martin Bailey found that 56% of respondents unsubscribed from emails because the content was no longer relevant. Avoid losing subscribers by providing focused, relevant content.
  2. Make it actionable: Your email content should provide actionable insights that your subscribers can apply immediately. For example, if you're sharing tips on writing a small business plan, you can break down the process into easy-to-follow steps and include templates or tools to help your subscribers get started. By offering practical solutions, you're providing value and building trust with your audience.
  3. Use data to support your points: To establish credibility, back up your claims with research, case studies, or statistics. According to a study by the Content Marketing Institute, content with data is 30% more likely to be shared. For instance, when discussing the importance of a small business plan, you can mention that businesses with a plan are 2.5 times more likely to secure loans and attract investors.
  4. Personalize your content: Personalization helps create a connection with your audience and makes your content more engaging. Address your subscribers by their first name and tailor your content to their interests or preferences. According to research by Experian, personalized email campaigns show a 29% higher open rate and a 41% higher click-through rate compared to non-personalized emails.
  5. Use storytelling: Engaging stories can make your content more memorable and relatable. Share personal experiences, anecdotes, or case studies that illustrate your points. For example, you can share a story about a small business owner who successfully wrote and implemented a business plan, leading to significant growth and success.
  6. Format your content for readability: Make your emails easy to read by breaking up long blocks of text, using bullet points, and incorporating bold or italicized fonts for emphasis. Research by the Nielsen Norman Group found that users read only about 20% of the text on a webpage. Make your content scannable to ensure your subscribers quickly absorb the main points.
  7. Include a clear call-to-action (CTA): Encourage your subscribers to take the desired action by including a clear, compelling CTA. Whether you want them to download a guide, sign up for a webinar, or make a purchase, make sure your CTA is easy to find and understand. According to a study by WordStream, emails with a single CTA increased clicks by 371% and sales by 1617%.

Step #5: Measure Your Subject Line's Success

To evaluate the effectiveness of your email subjects, you can analyze:

  1. Client/customer inquiries – do your emails generate interest and inquiries from clients or customers?
  2. Social media stats – how many times is your content shared on social media platforms?
  3. Inbound links generated – are you receiving editorial links that pass SEO value to your web pages and improve search rankings?
  4. Direct responses – analyze comments and engagement to determine which subject lines are working and which aren't.
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