How to A/B test your marketing email subject lines
If you’ve been busy growing your email list and feel ready to level up your email marketing game, now is the time to try out some A/B testing (also known as split testing).
You’ll get the best results from A/B testing if you have a fairly large subscriber base - at least 200 contacts. If your list is under 200 then you won’t see enough difference for the test to be meaningful. Save this advanced tactic for a later date when your list has grown some more.
What is an email A/B test?
Put simply, A/B testing is creating two almost identical emails, sending them both out to a small segment of your mailing list (not everyone on the list!) and noting which email performs the best.
The test should go out to between 20-30% of your total audience. Half will be sent to version A and half version B.
Then you send the winning email to the rest of your list and benefit from improved results over sending just one email with zero testing.
Which part of the email should I A/B test?
I advise starting with A/B testing the subject line. A/B testing an email subject line looks at the open rate (what percentage of recipients opened the email) to decide the winner. The more people that open the email, the better!
How to A/B test your email subject line
With the subject line, I advise you to create two very different versions. It won’t be a significant enough result if you simply switch a couple of words.
Here’s an example of a strong subject line A/B test:
[SUBJECT LINE A] How to save the planet 🌎
[SUBJECT LINE B] Kelly, some great ideas to live more sustainably
Subject line A is shorter and uses an emoji where subject line B is personalised with the recipient’s name and positions the content a little differently.
Hopefully you can see the big difference between the two subject lines.
If you need some help coming up with creative email subject lines, check out my FREE guide: 10 email subject line tactics to get your emails opened.
When testing a subject line - that is the only part of the two test emails that is different. The email content is exactly the same for both emails. Otherwise it’s not a fair test.
Most email marketing providers facilitate A/B testing and will provide a wizard to take you through set up. You’ll be notified of the winning email when results are in and can choose which version to send out to the remainder of the list.
I believe it’s worth switching email marketing providers if yours doesn’t offer A/B testing as it is such a powerful tool for getting better results with your campaigns. You may be surprised by the winning subject line and learn more about what resonates with your audience by undertaking regular A/B testing.
Conclusion
A/B testing (or split testing) your marketing email subject lines is a great way to improve the open rate of your email campaign. It works best if you have over 200 subscribers as the test will need to be sent to around 25% of your subscriber base to get a result.
Make the two subject lines very different from each other and wait for the winning email results to come in. It’s important to keep everything else about the email the same or it’s not a fair test.
If you are looking to do more email marketing and feel like you could benefit from more of my advice, take a look at my Email Marketing Toolkit. It could be just what you need to progress your email marketing activity.
