5 tips for subject line testing your email marketing campaigns

My Clients Often Ask How They Can Improve Their Open Rate

I’m a big advocate of testing and I spend a lot of time helping clients run tests to find out exactly what works for their brand. Most are familiar with the different types of testing, but aren’t performing tests on a regular basis. An easy test that every client should be doing on a regular basis is testing subject lines.

47% of email recipients decide whether to open or discard a message based exclusively on the subject line, and 69% report an email as spam depending on their impression of it.

Subject line testing is easy because, unlike other kinds of testing, it doesn’t require a lot of extra time and resources. And it’s a great way to help you determine what your audience responds to best.

Where Do You Start With Subject Line Testing?

I had a client that tested out a subject line of “Do Not Open This Email” and they saw GREAT results.  It worked well for their brand and the products they sold, but you always have to keep in mind that a lot depends on what your business is selling, how you typically speak to your contacts, and what’s “on brand” for you.

With that in mind, here are a few general ideas of different types of subject lines to test.

  • Simple and Direct (Shop our X New Products Now)
  • Benefit Oriented (Gift giving just got easier..)
  • Exciting News (This Just In…..)  
  • How To (Brew amazing coffee…)
  • Provocative Question (Are You Ready For….)
  • The Command (You Need this in Your Life‏)
  • The Teaser (Have we got news for you….)
  • The Reminder: (Last day to save X%.)

Verbiage Isn’t the Only Opportunity When It Comes to Subject Line Testing

Another element of the subject line that is worth testing is the length of your subject line.

According to one study, the sweet spot for an email subject line length in 2019 is 41 characters–or 7 words, which is about 10 characters less than the average subject line.

Something important to keep in mind is that so many more folks are checking their emails on mobile devices which don’t allow the luxury of long subject lines. In fact, about 3 in 5 consumers check their email on the go (mobile) and 75% of say they use their smartphones most often to check email.  If you have a lot of contacts that are opening on mobile, you’ll want to keep the subject line length in mind. With mobile’s truncated display of the subject line, typically 30-40 characters are displayed. Keep that number in mind when creating your subject lines if you have a mobile heavy list. Additionally, you can always consider testing long v/s short subject lines for all your contacts, no matter what device they are using to open your emails.

In addition to the verbiage and length of subject lines, there are other things that impact open rate that could really have an impact such as:

  • Sender name
  • Time of Day
  • Day of the Week

After you nail down the types of subject lines that your audience responds best to, you should start testing these other ideas to see what moves the metrics even more.

Conclusion: Always Be Testing

In general, you should test, test and keep testing whenever your email calendar allows for it. Subject line testing is easy and produces quick results. Keep in mind, you’ll want to test one type of subject line idea multiple times to ensure that you really have a winner or loser. Additionally, be sure to test different times of the year as well. You may find that certain types of subject lines work better during the holiday season than the summer months.  Hopefully this has sparked some ideas for you. Happy testing!

Have questions about any of these ideas? Our experienced strategy team has helped hundreds of clients implement them, and they’d be happy to help you, too! Just reach out.

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