Best Practices for Email Subject Lines

Here are twenty-one tips for writing effective subject lines. 

1. The top-performing word used in email subject lines is “Thank you.”
2. Subject lines with multiple topics separated by pipes have the second highest open rate. For example: Thank you for entering |10% off Site-wide.
3. Email autoresponders with subject lines that confirm entry to a contest or giveaway have a 46.9%** open rate.
4. Subject lines with three words have a 25% higher open rate than seven-word subject lines. Since 40 percent of emails are opened on mobile devices, make sure people can read the entire line from their phone or tablet.
5. A/B test the sender. You can test open rates that compare what happens when the sender is your company name vs. the name of someone at your company. For example, “James Belosic” vs. “ShortStack.”
6. Personalize the subject line. If you’re sending a birthday or other holiday-related offer, using the recipient’s name in the subject line is attention grabbing. For example, “Happy Birthday, Jenny! We have a gift for you.”
7. Send at the right time. According to SendGrid, Tuesday at 4 p.m. is the best time to send email, but as soon as everyone gets wind of that, the best time will change so to figure out the best times for your lists, you have to test.
8. Use action words.
9. If you’re promoting a new product or service, use NEW as the first word of your subject line. For example: “NEW: Our most requested feature is live!”
10. Make the message feel exclusive.
11. Add a sense of urgency using words like “soon,” and “tomorrow” which have 25% higher open rates than “now” or “today.”
12. If you’re offering a discount on your product “10% off” in your subject line is more likely to increase open rates than “50% off” is (go figure!).
13. Ask a question.
14. Include a call to action.
15. Never use all caps (and try to avoid exclamation points!).
16. Avoid special characters.
17. If you’re targeting by location, use location in the subject line.
18. Always A/B test subject lines.
19. Avoid words like “Journal,” “Whitepaper” “Forecast” and “Training,” because subject lines with these words tend to have low open rates. Other poor performers include “Subscription,” “Early bird,” “Industry” and “Report.”
20. Avoid using links and hashtags in your subject lines; open rates with either of these drop to 10.5%.
21. Never bait and switch. The content of your email should deliver what you promise in the subject line. If it doesn’t, get ready to see your unsubscribe rate skyrocket.