The Importance of A/B Split Testing For Your Email Marketing Efforts

posted this in
Content Marketing
on January 27th, 2011

The life of an email marketer is a little like that of a research scientist (but with fewer test tubes and white lab coats): constant tweaking, testing and experimenting.

Improvement is an important aspect of successful email marketing. There are an infinite number of details in an email campaign that can affect its overall success. Since no two email lists are the same, it is extremely important to test these details in order to maximize your email marketing efforts. One of the best ways to do this is through A/B split testing.

How do you get started?

Email A/B split testing is the process of sending two different emails to analyze the better performer. When creating a split test, remember to:

  1. Determine what metric will decide success – Before you begin your test, you need a way to determine which version will be the winner. You want your recipients to do more than open your email. Click through rates and conversions usually give the most accurate view of your email’s success.
  2. Test one thing at a time – If there are numerous differences between the two versions of your email, it will be difficult to determine the aspect that had the positive impact. For example, what if you tweaked the time of send and the subject line? Perhaps the time of send increased the click rate by 14% but the subject line decreased it by 13%. You would only see a difference of 1% between the two emails and be unable to attribute the difference to one specific change.
  3. Test, measure, improve, repeat – There is no end to A/B testing for email marketers. You will eventually gain a better understanding of what gives the best results, but you should never assume you’re done. There is always room for improvement and the only way to do so is through constant testing and measuring.

What should you test?

Now that you better understand what to consider when creating an A/B split test, here is a list of a few of the most important things you should be regularly analyzing in your email campaigns.

Time of send

For most businesses, it is ideal to send your emails first thing in the morning. However, this depends on the location of your recipients, among other things. Also, “morning” is a loose term. Does sending your email campaign at 5:00 a.m. give you better results than sending at 8:00 a.m.? How will you know unless you test?

In our testing of send times, we have found 8:00 a.m. to be the best time for many of our service-oriented businesses. However, some of the lists we manage receive better response times at 7:00 a.m. and earlier. The only way to know for sure is to continually A/B test.

Day of send

Does your list respond more to middle of the week emails or weekend emails? Most people read their email at different times depending on the day of the week. Coordinate this test with your time of send tests, as well. 8:00 a.m. Wednesday might perform better than 10:00 a.m. Thursday but not as well as 7:00 a.m. Tuesday. Remember to also consider holidays, as they also affect people’s email reading habits.

Subject line

The subject line is a preview of what your recipients can expect in the email. It is often what people use to decide whether or not to open your email. For this reason, you want to make sure your subject line is optimized to maximize your clicks. Your subject line should be concise and informative while enticing your recipients to open and click your email. See our tips for creating better email subject lines.

From line

When someone receives your email, who will appear in the “from” line? People tend to first look at the sender then the subject line to see if they believe the email is worth opening. To avoid deletion or being reported as spam, make sure your from line is easily identifiable by your recipients. You can test using an email address (i.e., your company name or a person in your company.


A well-organized layout increases conversions and leads while a poorly constructed layout has the opposite effect. It doesn’t matter how pretty your email looks if it doesn’t perform. Create multiple layouts and test them to see how they compare. Do bigger pictures or buttons make a difference? Should you have more text or less? Find out what elements make for an effective email newsletter.


Good content is essential to successful email marketing. You can do everything else perfectly, but if you don’t have compelling, first-rate content, your email marketing efforts will be a disaster. Find out what types of content works best for your target audience by creating different articles and offers and A/B split testing them. Don’t forget to test and analyze the wording of titles, as well.

Let’s recap

Email marketing is one of the most effective ways to keep your brand in front of your customers. It also serves as an instrumental tool for lead nurturing. But in order to get the most out of your email efforts, you must perform regular A/B split tests on your campaigns and eBlasts. Like an experimental scientist, sometimes your formula will work and sometimes it won’t. But you will always learn something in the process.

Have a question for our email marketing experts? Contact Rocket Media online today. Or, if your business is looking for help getting started with your own email marketing efforts, request a quote.