How to A/B Test Your Email Subject Lines and Improve Your Email Drip Campaigns

Last updated on: April 19, 2024

A/B testing, also known as split testing, is a marketing technique that involves comparing two variations of a marketing element to see which performs better. In the case of email marketing, A/B testing can help you optimize your email subject lines to increase open rates, click-through rates, and ultimately, conversions. A/B testing can be especially helpful for improving email drip campaigns, which are a series of automated emails sent to subscribers over time. In this post, we’ll cover the steps you need to take to A/B test your email subject lines effectively and improve your email drip campaigns.

Step 1: Define your test hypothesis

The first step in A/B testing your email subject line is to define your test hypothesis. In other words, what do you want to test and why? Your hypothesis should be specific and measurable. For example, you might want to test whether using a question in your subject line increases open rates in your email drip campaign. Your hypothesis might be, “If we use a question in the subject line of our email drip campaign, we will see a 20% increase in open rates.”

Step 2: Decide on your variables

Once you’ve defined your test hypothesis, you need to decide on your variables. In the case of subject lines, you’ll be testing different variations of your subject line to see which performs better in your email drip campaign. You could test variables such as:

  • The length of the subject line
  • The use of emojis or other symbols
  • The use of personalization
  • The use of different types of language (e.g., urgent vs. casual)

Step 3: Choose your email segments

Next, you need to choose the segments of your email list that you’ll be testing your subject lines on in your email drip campaign. You’ll want to choose a large enough sample size to ensure that your results are statistically significant. Depending on the size of your email list, you might choose to test your subject lines on a random subset of your list, or you might choose to split your list into two equal segments.

Step 4: Create your test emails

Now it’s time to create your test emails for your email drip campaign. You’ll need to create two different versions of your email, with the only difference being the subject line. Make sure that everything else in the email (such as the content and the call to action) is the same, so that you can be confident that any differences in performance are due to the subject line.

Step 5: Send out your test emails

Once you’ve created your test emails for your email drip campaign, it’s time to send them out. Depending on the size of your email list, you might choose to send them all at once, or you might stagger the send times to ensure that you get an accurate picture of performance.

Step 6: Measure your results

After you’ve sent out your test emails for your email drip campaign, it’s time to measure your results. You’ll want to look at metrics such as open rates, click-through rates, and conversion rates to see which subject line performed better. Ideally, you should wait until you have a statistically significant sample size (typically at least 100 responses) before making any conclusions.

Step 7: Draw conclusions and implement changes

Once you’ve measured your results for your email drip campaign, it’s time to draw conclusions and implement changes. If one subject line clearly performed better than the other, you can implement that subject line in future emails in your email drip campaign. If the results are inconclusive, you might need to do more testing or adjust your variables.

Here are some additional tips to help you get the most out of your A/B testing and improve your email drip campaigns:

  1. Test at different stages of your email drip campaign: A/B testing your subject lines is not a one-and-done activity. You should test different variables at different stages of your email drip campaign to see which subject lines perform best for different types of emails. For example, you might find that using a personalized subject line works best for your welcome email, but a more urgent subject line works best for your abandoned cart email.
  2. Consider the timing of your test emails: The timing of your test emails can also have an impact on your results. For example, you might find that a certain subject line performs better on weekends than on weekdays, or that a certain subject line performs better in the morning than in the afternoon. Consider these factors when planning your A/B tests for your email drip campaign.
  3. Use A/B testing software: A/B testing your email subject lines manually can be time-consuming and prone to errors. Consider using A/B testing software, such as ConvertFlow or OptinMonster, to automate the process and get more accurate results.
  4. Test other elements of your email drip campaign: While A/B testing your subject lines is important, it’s not the only element of your email drip campaign that you can test. You can also test other elements, such as the timing of your emails, the length of your emails, and the design of your emails.

Conclusion

A/B testing your email subject lines is an essential part of any email marketing strategy, especially for email drip campaigns. By testing different variables and measuring your results, you can optimize your subject lines and increase the success of your email campaigns. Remember to define your test hypothesis, choose your variables, and measure your results accurately. Additionally, consider testing at different stages of your email drip campaign, using A/B testing software, and testing other elements of your emails. With these tips and strategies, you’ll be well on your way to creating effective email drip campaigns that convert.