Subject Lines

Last updated: 
June 10, 2022

Recipients glance at each subject line for only a couple seconds before deciding whether or not to open an email. Needless to say, the subject line is a critical part of each message. MailerMailer analyzed the subject lines of more than 1.2 billion messages to identify subject line trends. According to our findings, relevant and persuasive words are frequently chosen to craft subject lines. Additionally, brief subject lines entice the highest open rate, while moderately long subject lines are associated with the highest click rate.

Subject Line Trends: Most Popular Words

The top 100 words used by our customers are represented in the tag cloud below wherein size and shade of each word correlate with frequency of use. According to our results, words such as news, free, tonight, party and sale reigned as the most popular choices. Other popular choices include newsletter, night, and weekend.

These choices indicate that customers strive to make their subject lines relevant (news, newsletter) and persuasive (free, party, sale), as well as emphasize time sensitivity of the message (night, weekend).

How to find the right keywords to ensure you are using words that will resonate with your readers try using Google Keyword Tool to research the most fitting keywords for your content.

Open Rates by Subject Line Length

Like last year, short subject lines, specifically with less than 15 characters, boasted the highest open rate (15.2%). The longest subject lines, containing over 51 characters, resulted in the lowest open rate of 10.4%.Unlike last year’s data, the trend between 16 and 50 characters is weak, showing neither a steady decline nor increase.

Start Driving Engagement with Subject Line Pro

Save time and improve results with virtual subject line testing that delivers real, accurate results in seconds. Get as much as a 21% lift in performance!

Request a Free Consultation

Tell me how I can get started with Subject Line Pro!

Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.

Click Rates by Subject Line Length

Click rates plotted over subject line length resulted in a normal distribution, similar to last year’s findings. The highest click rates were experienced by emails with 28 to 39 characters in the subject line. Rates decline as one approaches shorter or longer subject lines.

Without further data, the relationship between these metrics remains in speculation. July 2012 Edition

Schedule a Call

Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.