What Is A/B Testing In Email Marketing: The Ultimate
Guide For SaaS Businesses

AB Testing In Email Marketing


One of the wonderful things about email marketing is that you can do a lot of things with it. There are a lot of possibilities on how you could craft a marketing email.

Your email could be educational, promotional, or a mix of both. It could have a lot of images or almost none at all. You could use a personal tone or a more formal one. You could make it long or short.

You get the idea – there are a lot of options available to you. And that’s a great thing.

Having options is always good. But it also means that you have to make choices, and sometimes those choices can be tough.

What if you’re not sure what will work best for your email list? What if you want to try out a few different things but you don’t want to risk alienating your subscribers?

This is where A/B testing comes in. It is one of the most essential practices you need to do when you’re running a SaaS email marketing campaign.

But what is A/B testing in email marketing?

In this blog post, we will answer that question and discuss more things about email A/B testing that SaaS businesses should know.


What Is A/B Testing?


A/B testing, also called split testing, is a method of experimentation where you compare two versions of something to see which version performs better.

And since we’re talking about email marketing here, we’re going to talk about split testing different factors in your email marketing campaigns.

First, let’s get on the same page regarding some common terminologies being thrown around in email AB testing:

Variable: A factor that you want to test in your email. It could be the subject line, the call-to-action (CTA), the sender name, or anything else that you want to experiment with.

Combination: The different combinations of the variables that you will be testing. For example, if you’re testing the subject line and the CTA, then your possible combinations would be:

  • Subject Line A + CTA A
  • Subject Line A + CTA B
  • Subject Line B + CTA A
  • Subject Line B + CTA B

Control: The original email that you send to your list. It could be an email that has been performing well or an email that you think is your best shot. Basically, it’s the email that you’re going to compare your other combinations with.

Version or Variant: A variation of the control email. It contains one or more changes (variables) that you want to test.

Test Group: A small group of people (usually a sample size of 1,000 recipients) who will receive a different version of your email. This group is usually chosen at random from your list.

Winning Email or Winning Variant: The email variant that performs better than the others and is, therefore, the “winner” of the test.

In email split testing, you create two versions (Version A and Version B) and send them out to a small test group.

After a period of time has passed, you analyze the results and see which performed better. From there, you can make changes to your email campaigns based on what you learned.

It’s important to note that A/B testing is not just about making changes for the sake of change. 

The goal is always to improve your results, whether that means more clicks, more opens, more sales, or whatever metric you’re tracking.


Benefits of A/B Testing Your Emails


There are several benefits that come with A/B testing your emails, which we will discuss in more detail below.


It Helps You Understand What Your Email Subscribers Want


One of the great things about A/B testing is that it helps you understand what your target audience really wants.

This might seem like a no-brainer, but it’s actually quite important.

You can have all the ideas in the world about what would make a great email, but if it doesn’t resonate with your subscribers, then it’s not going to do you any good.

As an email marketer, it should be important for you to know what topics and approaches can best reach your target audience.

But even the most thorough market research can only do so much. At the end of the day, nothing beats real-world data when it comes to understanding your email subscribers.

A/B testing can give you that data.

After all, your results from split testing come from real responses from real email subscribers.


It Is A Safe Space To Try Out New Things


We get it – change can be scary, especially when it comes to something as important as your email marketing campaign.

But sometimes, change is necessary if you want to see results.

If you’re not seeing the results that you want from your email campaigns, then maybe it’s time to try something new.

But instead of just making changes willy-nilly, why not test those changes first?

This is where split testing comes in handy. It allows you to try out new things without the risk of alienating your entire email list.


It Helps You Improve Your Open Rate & Click-Through Rate (CTR)


If you can improve your open rate and click-through rate (CTR), then that’s going to have a positive impact on your business.

And A/B testing can help you do just that.

By split testing different elements of your email marketing campaigns, you can find out what works best for your list and make changes accordingly.

Over time, those small improvements can add up to big results.


It Increases Your Revenue


At the end of the day, the goal of any business is to make money. And if A/B testing can help you do that, then it’s definitely worth doing.


Well, if you can increase your open rate and CTR, then you’re more likely to make sales. And if you can make more sales, then you’re going to increase your revenue.

It’s as simple as that.


What You Need To A/B Test In SaaS Email Marketing


Now that we’ve talked about the benefits of A/B testing, let’s take a look at some of the different things you can test in SaaS email marketing.


Subject Lines


Your subject line is one of the most important elements of your email because it’s what gets people to open your email in the first place.

That’s why it’s important to split test different subject lines and find out which ones work best for your list.

Some things you may want to consider testing include:

  • The length of your subject line
  • The use of emojis
  • Asking a question
  • Using numbers or symbols


Your “From” Name


Your “from” name is another variable that you need to optimize to improve your email open rate.

This is because it helps people decide whether or not to open your email. If they don’t recognize the sender, they’re less likely to open it.

That’s why it’s important to test different things in your “from” field and find out what works best for your list.

Some things you may want to consider testing include:

  • The name you use
  • The email address
  • Whether or not to include your company name

Whether to include your name or your SaaS company’s name ultimately depends on your target audience.

If your split test shows that more people respond to emails with your name on them, your email subscribers may be looking for a personal touch in your messages. This may work if you, as an individual, have an established authority or thought leadership in your niche.

On the other hand, if your target audience responds better to emails from your company, they may be more interested in official-sounding communications. This is generally true with business-to-business (B2B) audiences.


Preview Text


Your preview text is the short summary of your email that appears next to the subject line in people’s inboxes.

It’s important to remember that people will see your preview text before they even open your email, so it needs to be effective.

Some things you may want to consider testing in your preview text include:

  • The length of your preview text
  • The use of emojis
  • Asking a question
  • Using numbers or symbols
  • Adding your CTA in your preview text


Email Content


Of course, the actual content of your email is also important. After all, that’s what people are going to read when they click on that subject line.

So it’s important to put different things in your email content and find out what works best for your list.

Some things you may want to consider testing include:

  • The length of your email
  • The use of images
  • The use of videos
  • The use of GIFs
  • HTML VS plain text


Calls-to-Action (CTAs)


Your call-to-action (CTA) is what tells people what you want them to do after reading your email. It could be anything from visiting your website to signing up for a free trial.

Whatever it is, you need to make sure that it’s effective. And the best way to do that is to split-test different CTAs and see which ones get the best results.

Some things you may want to consider testing in your CTA include:

  • The color of your CTA button
  • The size of your CTA button
  • The CTA text
  • The placement of your CTA button
  • The number of CTAs in your email

Your CTA should be simple and to the point. It should be easy for people to understand what you want them to do.

And it should be placed in a spot where people will see it. That’s why the placement of your CTA button is so important.


Word Order


The word order in your email can also have a big impact on how people respond to it.

Let’s have two versions of a CTA for example:

Version A could be “Download our ebook and get a free trial.”

While version B could be “Get a 14-day free trial when you download our ebook.”

While both versions have the same offer, they present it in different ways. See how one focuses on the ebook while the other focuses on the free trial?

The thing is that there is no single correct word order to this CTA. People may respond differently to each version.

So it’s important to test different word orders in your email and see which ones get the best results.




People are more likely to respond to emails that feel personalized. That’s why it’s important to personalize your emails as much as possible.

Some things you may want to consider personalizing in your email include:

  • The recipient’s name
  • The recipient’s company name
  • The recipient’s title
  • The recipient’s location

You can also use merge tags to insert different information into your email depending on who the recipient is. This is a great way to automatically personalize your messages.


Send Time


The send time for your email can also have a big impact on how successful it is.

Generally, people tend to check their emails sometime around 10 AM, 1 PM, and 6 PM. So those are generally good times to send your messages.

However, it’s important to test different times and see when your audience is most engaged.

You may find that people on your list are more likely to open your emails early in the morning or late at night. So it’s essential to experiment and find out what works best for your list.




You also need to test out how often you are sending your marketing emails.

If you send too many emails within a short span of time, people may start to get annoyed and may even unsubscribe from your list. But if you don’t send enough, people may forget about you.

So it’s important to find a balance. And the best way to do that is to experiment and see what works best for your email list.

You may find that your email subscribers prefer getting one email per week or one email every other day. It all depends on your audience.


Email AB Testing Best Practices


Now that you know what you can test, let’s take a look at some best practices for email AB testing.


Use A Reliable Email AB Testing Tool


If you’re using a leading email marketing software like Mailchimp or Campaign Monitor, the good news is that they already have built-in AB testing features. These make it easy to set up and run your tests.

However, your email marketing solution doesn’t have a built-in AB testing tool, there are still plenty of great options out there.

Some of the best AB testing software for email include:

  • Optimizely
  • Convertize
  • Google Optimize
  • AB Tasty
  • VWO


Pick The Right Variables To Test


There are a lot of different variables that you can test in your email. But you don’t want to try and test everything at once. That would be too overwhelming.

Instead, start with one or two variables and test those first. Once you have a good understanding of how those work, you can move on to testing other things.

And as we mentioned before, it’s important to focus on the variables that are most likely to have an impact on your results.

For example, let’s say you’re doing a split test for some lead nurturing emails. You could focus on variables that have something to do with the open rate, like subject lines and preview text.

It would be different if you were testing promotional emails. In that case, you may want to focus on variables like the CTA or the email content.


Start With A Small Sample Size


When you’re first starting out, it’s important to keep your sample size small.

You don’t want to send the same emails to your entire email list. That would make it hard to compare the results of your test.

Instead, start by sending your email to a small group of people. Then, once you have the results, you can decide whether or not to roll it out to your entire list.

This also makes it easier to track the results of your tests. If you’re only testing a small group of people, it will be easier to see how each variable impacts your results.


Form Your Sample Groups Randomly & Equally


When you’re forming your sample groups, it’s important to do it randomly and equally.

For example, let’s say you have a sample size of 100 people. You want to split them into two groups of 50.

To do that randomly, you can use a group randomizer or a random team generator. This will help ensure that each person has an equal chance of being in either group.

Once you have your groups, it’s important to make sure that they’re equal in terms of size and demographics.

This is important because you want to make sure that the only difference between the two groups is the variable that you’re testing. If there are other differences, your results won’t be as accurate as they could be.


Test Variations Simultaneously


When you’re testing two versions of the same email, it’s important to test the different variations at the same time.

This is important because you want to make sure that the results of your test are not affected by external factors, like trends that change over time.

If you test one variation first and then test another later, there’s a chance that the results could be skewed.

To avoid this, run your tests at the same time and for the same amount of time. This way, you can be confident that any differences in results are really due to the variable that you’re testing.


Ensure A Significant Difference Before Declaring A Winning Variant


When you’re looking at your results, it’s important to make sure that there’s a significant difference between the two groups before you declare a winning email.

A small difference may not be statistically significant. That means that it could just be a fluke and not indicative of the entire population.

To determine whether or not the difference is significant, you can use a statistical significance calculator. You may use free-to-use split test significance calculators like the ones VWO and SurveyMonkey offer.

These tools will help you figure out if the results of your test are reliable.


Keep Testing


Once you’ve run your first few tests, it’s important to keep testing.

The world of email marketing is always changing. What works today may not work tomorrow. So it’s important to keep up with the latest trends and best practices.

And as your business grows, your email list will change too. You’ll have new subscribers coming in all the time. So you’ll need to adjust your emails accordingly.

The only way to do that is by constantly testing and experimenting.

Over time, you’ll develop a good understanding of what works and what doesn’t. And you can use that knowledge to create even more successful email campaigns.


A/B Testing In SaaS Email Marketing: Final Thoughts


A/B testing is a powerful tool that can help you improve your email marketing campaigns. By testing different variables, you can figure out what works and what doesn’t.

But it’s important to remember that A/B testing is not a magic bullet. There’s no guarantee that you’ll find the perfect combination of variables on your first try.

It takes time and effort to find the right combination. But it’s worth it in the end.

When you find a winning combination, you can use it to create more successful email campaigns that will help you achieve your goals.

Want more guides and tips that can help you grow your SaaS business? Visit our blog here.

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Ken Moo