Unless you test.

It’s only by testing that you can continue refining your email marketing campaigns, improving open rates, conversion rates…and ultimately email marketing ROI, right?

The easiest way to test email marketing campaigns is with an A/B split test. An A/B split test means splitting your list into two, then trying two different things with it (like two different subject lines). Whichever one performs better tells you something. Maybe a shorter, more promotional subject line performs better than a longer, dryer one. That tells you your audience might prefer the shorter, more sales-y subject lines, and you can use that knowledge going forward for your next email marketing campaign.

You can test pretty much any email marketing and design component in your email campaigns:

• From names
• Subject lines
• Personalization
• Offers
• Calls to action
• Images
• Delivery days or times
• Click throughs
• Amount of copy
• Type of content
• Html vs. text
• Frequency
• Layout

To do an A/B split test, divide your list into two groups: one is A, one is B. Now change one, just one, thing about the emails between them. (If you have more than one variable, you can’t accurately measure your results.) Then send out your emails to both groups at the same time (to avoid the time variable). Finally, compare your results and learn. That’s all there is to it.

You can either do an A/B test to your entire list (if it’s small), or you can do an A/B to a statistically significant size portion of your list. Your email test group should be at least 10,000 email addresses to be statistically significant.

Wait, there is one more step: Keep on testing. Make it a habit. If you do, you’ll keep on learning, improving, and increasing that email marketing ROI.