Effective email marketing: 6 essential tips for A/B testing subject lines

4 minute read
Effective email marketing: 6 essential tips for A/B testing subject lines

A/B testing, otherwise known as split testing, can help you determine the email subject lines that are more likely to engage your target audience.

Simply put, the A/B testing process of sending two versions of an email to two similar but separate audiences. And, of course, this can be done with two versions of just the email subject line as well. 

Email subject lines are just one type of A/B test. You also can test the call-to-action, template design, images, text copy within the email, personalization, and coupons.

The goal of these tests is to find which variation best meets your marketing priorities. Once you’ve found the most successful way to present your email, you can then send it to the rest of your audience. This means that you can pivot your email campaign in real-time.

Only about 61 percent of marketers use A/B testing to improve their marketing performance, so the opportunity is there to beat out your competition.

A/B testing email subject lines can feel overwhelming, but the following are six tips to help you test effectively, how to approach testing subject lines specifically and boost your email open rates as a result.

Focus on One Variable for Accurate A/B Test Results

It’s tempting to test more than one aspect of your email to speed up the testing process, but your data won’t be accurate if you do so.

You want to focus on just one variable at a time so that you know exactly what change has impacted the behavior of your email recipients. 

Establish a Control Group for Effective A/B Testing

When A/B testing email subject lines, start by using the original, unchanged version of the email as a “control.”

This will give you a baseline that you can measure your results against. Having that helps ensure that your data is as accurate as possible.

Strategically Select and Segment Recipients for Testing

Consider which members of your audience you want to use for your A/B testing, and then split them in a random way. 

Make sure that each half is only getting one of the two versions of the email subject lines. DailyStory offers the ability to create experiments with all of your outbound marketing to see how different content performs.

Timing Consistency: Key to Reliable A/B Test Data

To ensure A/B testing efficiency, your control and adjusted email testing subject lines must be sent out at the same time on the same day. 

Otherwise, you risk experiencing seasonal highs and lows, as well as timing being an unintentional variant that you’re testing.

Importance of Statistical Significance in A/B Testing

Keep in mind that if you’re sending a very small batch of A/B testing emails, the differences could actually be happening due to random chance.

Commit to a larger testing batch, and watch out for a 5 percent or lower difference in results. Many A/B testing tools will rule out these negligible differences that larger decisions shouldn’t be based on.

Creative Strategies for A/B Testing Email Subject Lines

Email subject lines offer one of the biggest opportunities to increase your email open rates, and your open rate is arguably one of the most important metrics to increase in email marketing. This is because a recipient who doesn’t open your email is missing 99 percent of your message. (Click rate is also important, but recipients must open the email first in order to click anything inside of it.)

When planning your A/B testing of email subject lines, consider the following approaches to test:

  • Personalizing with the recipient’s first name
  • Specifying the type of content inside the email (such as a video) or not
  • Writing in first person versus second person
  • Using sentence-case versus title-case for capitalization
  • Including a product description or characteristic
  • Asking a question or making a statement
  • Begin vague or being specific
  • Experimenting with the character count
  • Including urgency or not
  • Using hyphens or colons
  • Leveraging gratitude
  • Using emojis or not

In conclusion

While A/B testing email subject lines will mean that some of your audience will receive a less effective subject line than others, keep in mind that you will ultimately send the most effective to a much larger group of your audience.

Successful A/B testing of email subject lines can boost your email open rates, so take your time and plan accordingly. The results are worth it.

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