Category: Email

Written by toomaime

Last Updated 🗓 4 years ago

Email Subject Line

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When writing Emails to your users always personalize it.

Email Subject Line

A little guide on how you can improve your email subject line and increase the open rate of your emails.


Before opening an email most people scan the subject lines in their inbox to decide which messages are worth to read. But what is the key for a good subject line? The email provider Mailchimp gives us an answer. They studied 24 billion delivered emails with subject lines composed of approximately 22,000 distinct words. Here is what they found out.

1. Personalization works

The analysis shows that it increase the open rates significantly. Even more, the use of both first and last names in a subject has the largest positive impact on open rates. MailChimp also points out that although the use of the first name has a positive impact on the open rate it is not the same in every industry. For example in the legal industry, the first name personalization has a negative impact on open rates. 

2. The word "free" 

The use of the word free does increase the open rate, but not in every industry. MailChimp suggests to avoid the word free in the medical, retail, and travel industries, but restaurant and entertainment industries can certainly benefit from it.

3. Urgency or importance 

A word like urgent or important shows a positive effect on open rates. Of course, you shouldn't use these words in every email but perhaps sometimes you need a little bit more attention. 

4. Use announcements and invitations 

Announcements and invitations perform in a much better way than cancellations and reminders. 

5. Frequently used word pairs 

Sometimes using the right pairs of words are increasing the open rate. MailChimp, for example, found out that people like them to be thanked. What they don't like it to hear from a "last chance". Also, they don't like to be asked to sign up to anything. 

6. Capitalization 

The last point that can have an impact on your open rate is capitalization of your subject line. Completely capitalized subjects have a positive effect. [1]


"Last day before this bundle goes away" - Email from Justin Jackson

"48 ways to improve your business" - Email from Justin Jackson

"The biggest software acquisition in history 💰"- Email from AngelList

"⏰ Time is running out" - Email from Revolut

Hey Tobias, could we ask a favour? 🤞 - Email from Revolut

"We just launched a free React course on Scrimba" - Email from Scrimba

"We have a new Secret 🙊" - Email from ProductHunt

"BLACK FRIDAY - 50% Off React, Node and GraphQL" - Email from WesBos

"Free Worldwide Shipping - 24 hours remaining" - Email from EndClothing


Futher TIpps:

  • Keep it short (under 40 characters) 
  • Ask a question
  • Include a deadline 
  • Add a list 
  • Make an announcement[2


[1Subject Line Comparison

[2] Good email subject lines 



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