Why You Need to Split Test Your Emails (and 4 Best Practices to Get Started!)

Wondering what subject line gets the most opens? Curious what call-to-action yields the most clicks? Unsure whether to use images or GIFs? There’s a simple way to find out once and for all: Split test your emails.

What is a split test?

Split testing (or A/B testing) is a method by which you can scientifically test the effectiveness of your email marketing. When split testing, you create two versions (called variants) of an email to determine which email statistically performs better. Once you find which email variant performs best, you can update your email strategy to include the winning email. This allows you to identify what emails engage your subscribers best, which can ultimately help you increase conversions and revenue.

Why you need to test your emails

Split testing is an effective way to find out what’s working and what’s not in your email marketing. Rather than assuming your customers would prefer one kind of email over another, you can run a split test to find out in a methodical way. The more you split test, the more information you’ll have on hand for your future emails. And while a once-and-done test, or even an occasional test, can yield information that will expand your marketing knowledge, regular testing can provide you with a successful email marketing strategy. Related: 6 Email Split Tests You Can Set Up in 1 Minute

4 best practices to get started

1. Test one element at a time.

Never test more than one change at a time. Have a control email that remains the same and a variant with one change — like a different color CTA button, or a different coupon offer — you want to test. If you have multiple variables, it’ll become difficult to identify which one caused a positive or negative result. For instance, let’s say you’re a blogger who writes about gardening. You decide to split test an email’s subject line to improve your open rates. The goal of your split test is to discover if longer, descriptive subject lines or shorter, direct subject lines perform better. You also want to see if including a subscriber’s first name in your subject line will increase your open rate. So you write two variant subject lines: Subject line #1: 3 Ways to Stop Weeds from Growing Before They Start Subject line #2: John, Stop Weeds Today. After looking over your analytics, you find that subject line #2 performs better. Great! But there’s a problem with your test: You don’t know why variant 2 performed better. Was it because of the first name? Or was it because the subject line was short and direct? To avoid this confusion, test one variable at a time.

2. Have a plan.

Prioritize your tests. Run split tests for your most important and most frequently sent emails first. And know what you want to fix about your emails before you run tests. Struggling with low open rates? Try subject line tests. Stuck with low click-through rates? Test your call-to-action button copy. Create a split testing plan where you conduct one email split test a week or one email split test per month.

3. Record your results.

Keep records of the email split tests you’ve performed, the results of those tests, and how you plan to implement your learnings. Not only will this keep you accountable for implementing changes, it will allow you to look back on what did and didn’t work.

4. Keep split testing.

You are never done split testing. Why? Because even if you find something that may be true of your subscribers now (for example, they like shorter subject lines), that may not be true three months or a year from now. So keep testing. The more you refine your email strategy through split testing, the more you improve your emails — and your bottom line.

Testing 1, 2, 3

Ready to discover even more split tests you can use to optimize your email marketing strategy? Check out our free Minimalist Marketer’s Guide to Split Testing to learn everything you need to know to become a split testing master.