The Best and Worst Words to Use in Email Subject LinesWhat you say in the subject line can be the key to whether or not people open the emails you send them. So the folks at British marketing firm Adestra reviewed over 2 billion global emails and put together The 2013 Adestra Subject Line Analysis Report that reveals which words get people to open your email and which words send them to the trash.

Below are some charts Adestra put together to illustrate their results. For each keyword, you will see the average deviation
from the mean for campaigns with subject lines
including that keyword.

What that means is, if the industry average open rate is 20%, and the word “Foo” results in 12% higher opens, that means that including the word “Foo” in the subject line resulted in a 22.4% open rate, or a 12% increase on 20%.

Overall BEST keywords in subject lines:

  • free delivery
  • alert
  • daily
  • subscription

Overall WORST keywords in subject lines:

  • only
  • learn
  • monthly
  • register

Overall Keyword Chart

Overall Keyword Chart

In B2B Publishing, the BEST keywords:

  • breaking
  • alert
  • editor
  • weekly
  • trial

In B2B Publishing, the WORST keywords:

  • forecast
  • report
  • newsletter
  • top stories
  • this week
  • subscription

B2B Keyword Chart

B2B Keyword Chart

In B2C Publishing, the BEST keywords:

  • review
  • update
  • video
  • daily
  • half price
  • limited

In B2C Publishing, the WORST keywords:

  • ? (a question mark)
  • win
  • monthly
  • discount
  • trial

B2C Keyword Chart

B2C Keyword Chart