9 Tips for Writing Email Subject Lines That Work

Every copywriter and journalist knows the importance of a powerful headline. A subject line can make or break your email. More than a third of subscribers decide whether or not to open your email based on the subject line alone, so we've compiled nine tips to write subject lines that work.

1. The 50/50 time-spent rule

When you create an email, how much time do you spend on the subject line? Some of the best marketers of all time suggest spending half of your time on the subject line alone.

Advertising legend David Ogilvy knew the power of headlines, and how the headline literally determined whether the advertisement would get read. He rewrote this famous headline for an automobile advertisement 104 times:

"At 60 miles an hour, the only thing you hear in the new Rolls Royce is the ticking of the dashboard clock …"

Master copywriter Gene Schwartz often spent an entire week on the first 50 words of a sales piece – the headline and the opening paragraph. Those 50 words are the most important part of any persuasive writing, and writing them well takes time.

Do you create the subject line last? If you write the message, find images and add a call to action first, you’ll be anxious to send it by the time you finish. That’s why you don’t want to create your subject line at the end. In an effort to get things done quickly, you might not spend the time needed to create and tweak a subject line like you should.

2. Keep it to 6-10 words

How long are your subject lines? You’ve likely heard tips to keep your subject lines brief, but that has a different meaning for everyone. Brief means 6-10 words, which research shows is the most effective subject line length. However, most marketers go over that limit and write subject lines that are 11-15 words long.

Subject lines that are 11-15 words pull in average open rates of 14 percent. Emails with 6-10 word subject lines have an average open rate of 21 percent.

3. Personalize it

If you have an email list with hundreds or thousands of contacts, how do you make each subscriber feel special? Use their name in the subject line. Personalize the email to make it feel like a message from a friend, rather than a company.

Personalized subject lines deliver 26 percent higher open rates, according to Experian Marketing Services.

4. Provide a sense of urgency

You want subscribers to act, so give subscribers a reason to do so. Send promotional emails with sale deadlines, tell subscribers when a product is about to run out or give subscribers one last chance to RSVP for your event.

Use urgent language too. Phrases like “Act Now,” “Today Only” and “Limited-Time Offer” are good examples.

5. Be specific

Don’t create a generic subject lines. Yes, you have limited space, but that doesn’t mean you can’t be descriptive. Running a sale? Tell subscribers what the sale is on and how much they can save. Hosting an event? Describe what it is in the subject line.

Generic subject lines like “Shop Now and Save” won’t have the success rates you’re looking for.

6. Be intriguing

Subscribers get hundreds of emails each day. How can you standout? Be intriguing. Try asking subscribers a question, quote a famous movie or use humor to grab a reader’s attention.

Try something out of the ordinary to capture attention, and get your subscribers to open your email and take action.

7. Be relevant to the subscriber

Subject lines should cater to the subscriber. Tell your audience why they should care about that particular email. If you create subject lines that focus on your business and not the customer, you’ll fail.

For example, a subject line that reads “Bob Smith Joined Our Team” is about your business, not the customer. A better subject line could be, “50% Off All Services From Our New CEO.”

8. Don’t go all salesy

You want to develop a lasting relationship with your subscribers. To do that, you can’t send a sales email every day. Sure, you want to increase revenue, but customers will be turned off if all they receive are sales pitches. Send an array of emails. From newsletters to how-to articles, diversify the content you send.

Before we go into tip number nine, we urge you to take the advice of superstar copywriter Clayton Makepeace and ask yourself these six questions…

Does your subject offer the reader a reward for reading? Will they benefit?
Can you include specifics to make the email subject more intriguing, believable and credible?
Will your subject trigger a strong (positive!), actionable emotion for the reader?
Will your subject topic immediately resonate with your prospect?
Could your email subject benefit from the inclusion of a proposed transaction?
Could you add an element of intrigue to drive the prospect into your opening copy?

Were you happy with your answers? If so, move on to the last (and extremely important) tip.

9. Test

Subject lines are one of the most effective components of an email to test. Run a split test. Take a small group of names from your contact list and split them into two lists. Each group receives the same email, but with different subject lines. See which one resonates with subscribers and use that when mailing the entire list.

By using these nine tips, you’ll create subject lines that resonate with your subscribers and help you build lasting, loyal relationships.