There have been numerous studies on the effectiveness of using certain keywords in email subject lines.

Alchemy Worx, a global email marketing agency, analyzed over 20 billion emails and concluded that these 20 keywords are the most effective, meaning that they got the highest open rates overall:

20. Upgrade

19. Just

18. Content

17. Go

16. Wonderful

15. Promotional

14. Congratulations

13. Forecast

12. Monthly

11. New

10. Update

9. Weekend

8. Alert

7. Breaking

6. Celebrate

5. Special

4. Latest

3. Revision

2. Deduction

1. Go

And now for the top 20 worst email subject line keywords.

These keywords got the lowest open rates, according to Alchemy Worx:

20. Friday

19. Miss

18. Deals

17. Groovy

16.  Conditions

15. Monday

14. Volunteer

13. Learn

12. Year

11. Finances

10. Healthy

9. Vacation

8. Test

7. Open

6. Urgent

5. Hi

4. Spam

3. Revolutionary

2. Exclusive

1. Buy

Regardless of which keywords you use, it’s important to be original. Studies show that the most original subject lines get the most opens.

And, as always, make sure the actual content of the email is worth reading.

For the top most creative email closing lines, click here, and for email closing lines to avoid, click here.

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