If you have been in the ‘throw it against the wall and see what sticks’ mode and have been praying that emails work because you followed all the ‘best practices’ from the self-proclaimed marketing guru, then you need to snap out of that.


Because there is a method to the madness and it’s called A/B testing. AB testing proves that marketing is not just a fuzzy activity but a scientific approach that produces quantifiable results.

What is A/B testing?

A/B testing or split testing in email marketing is the process of sending one version (version A) of your email to a subset of your broadcast list and sending another version to another subset.

Then you track a metric that will define the success of your test. This will show you which version out of A & B is better. And finally, you roll out that change across all your emails and that becomes your best practice.

Two versions of an email

It sounds simple in theory but the practical application has its own nuances. This short post will introduce you to some of the basics to get started.

The two things important to note are:

  • In both versions (A&B), there should be a difference of only one element or in other words, only one variable to test. E.g. only the color of CTAs is different, or only subject lines are different and the rest is identical. This is to make sure that you know exactly what changes affected your conversion.
  • Have a metric that will define the success of the test. If you are testing two subject lines, make sure that you can track your open rates. If you are testing the effect of long-form vs short-form copy, have a CTA in your email so that you know which one works better through click-to-open rate. Otherwise, by just open rates, you won’t be able to determine which copy worked better.

What elements should you test?

Some elements of an email will contribute more towards your goal than others. For example, changing your signature might not have a massive effect on click-through-rate but modifying your CTA can help boost conversions.

So you should devote the limited amount of time and resources we all (especially marketers who watch cat videos) have to test the most effective elements and ignore the rest.

Most impactful elements to test:

1) Subject line

Test out the effect of emojis, including the first name of the recipient, question mark, or including some relevant numbers in your subject lines. You can test shorter vs longer subject lines too.

Metric to measure the results: Open Rate

2) CTA

You can test the copy, placement, frequency, and design of the CTA. Of course, test one thing at a time.

  • For copy, for example, you can test between ‘Join Now’ & ‘Enroll Now’.
  • For placement, you can test above the fold vs below the fold.
  • Test one versus multiple CTAs in your email campaigns and see if there is any difference in the conversion rate.
  • Lastly, for the design, you can vary the color or size of CTA.

Metric to measure the result: Click-through-Rate

3) Send Time

There is no magic time of the day that works for all kinds of audiences. Depending upon your audience & type of newsletter, you can test various times and find the one optimal for you.  

For example, if you curate daily news sending at 8pm in the night might not be best as the news would have become stale by then. But if you are writing to part-time artists or coaches, you should send your email in the evening when your subscribers are free from their daily jobs.

Metric to measure the results: Open Rate

Wrap up

Have a culture of A/B testing in your email marketing strategy right from the start as it is a continuously evolving process. The behavior of the audience changes with change in technology, markets, and maturity of your product. So ‘Always Be Testing’.

The email marketing service you’re currently using may have an option for you to run and analyze the results from an A/B test.

If not, it’s no problem. You can try SendX for free 14-days and see what you think about their A/B testing functionalities, without even giving your credit card away.

SendX has helped 3000+ companies all over the globe to run, optimize, and scale their email marketing. You can do that too. Try it for 14-days for free. There is nothing to lose but a lot to learn.