A/B testing is the process of creating two different ways to sell the same product. It can be done with website design, where you present two different styles and user experiences. It can be done with paid ads, where you feature different sales copy. And it can be done with email marketing where you can send two different emails with different content, subject lines etc.

It is hugely powerful because you get to see what variables increase or decrease your open rates and click through rates. For example, you can change subject lines, perhaps one longer and one shorter, or with different words, and see which your audience responds to best.

It gives you insight that is quantifiable, and that can be used to improve your emails.

Your mailing list IS your business. Those contacts are your goldmine – you should think of every possible way to maximize conversion. A/B testing allows you to do exactly that and extract as much value as possible.

What Can You Test In A/B Testing?

  • Subject lines
  • Content
  • Images
  • From field
  • Time sent
  • Link to different landing pages
  • Layout

In Mailchimp here’s how you set it up and choose your variables.

Email marketing software like MailChimp is very sophisticated in that it will take a portion of your mailing list and send one variable to one half and the other to the other half. After a specified time period, the variable with the highest rate or click through rate wins, and will be sent to the remainder of the mailing list. This makes a big difference in your open rates and click through rates.

Examples Of AB Testing Results From My Own Campaigns

I do email marketing for a large training and education provider. The average open rate for this industry is 11%. We can beat that average with some simple subject line variations. I had to delete the subject lines to protect my client’s privacy but you’ll see the difference A/B testing can make. There was a 1.4% difference in open rates. For a mailing list of around 50,000 people, that’s an extra 700 people opening my email, and a lot more potential customers.


AB testing is about small tweaks and getting small improvements in open rates and click throughs but for large mailing lists or high value products, every 1% improvement can represent a huge amount of money gained in extra sales.

Is Mailchimp Free?

Mailchimp: This is the obvious first choice, being free for the first 2000 contacts in your mailing list. Here is a breakdown of Mailchimp paid plans. The Pro package costs $199. Alternatively, you can choose pay as you go where you pay for each email sent. This starts at $0.03 per email up to 5000, $0.02 up to 10,000 and $0.01 for over 50,000 emails. For example, if you have a mailing list of 10,000 people, each blast will cost you $200. That means if you’re sending more than 1 email a month, it’s worth spending the monthly fixed cost of $199 on the Pro package.

Cost: Free – $199

Other Good Paid AB Testing Tools I Use

Unbounce: Easy to use software for building and publishing landing pages. This is for landing page A/B testing, not email A/B testing, but you can integrate with Mailchimp and send different groups two different landing pages.

Cost: $49 – $200

AB Email Testing Tips

Salesy vs. descriptive: Mix up your subject lines with different vocabulary and tone. I.e, try some salesy subject lines with words like “buy now”, “free”, “don’t miss out”, “last chance”, “sale now on” etc. Then for the other variation, try more conservative language, simply describing the product or service instead of aggressively selling. You’ll quickly find out what kind of language your mailing list responds to best.

Email length: This is very powerful because you get to see whether your mailing list clicks through more on short emails or long emails. Try one email with just a few lines, and one with a whole page.

Call to action on buy or register buttons: Mix up the CTA on your buttons. Try things like the usual “Register Now” versus things like “Start Making Money Now”, or “Get This Beautiful Sweater Delivered Tomorrow”. You’ll have to play around and see what works, but definitely go beyond the standard “Buy Now” and “Register Now” CTA buttons.

Personal style vs. factual: One approach is to send emails as you would a letter, i.e. personal, as if you’re talking to that person, and writing in the first person (I), perhaps sharing personal anecdotes. The other is to be matter of fact , talking in third person and be purely factual.

Promotions: You can also test promotions like discounts and sales, or buy one get one free, by including a coupon code in one email but not in the other. You can see exactly how much impact your promotion had compared to a control group.

From Field: Mix up the name the email is from. I’l be honest, I have never gained any insight from the from field but I tend to think that names, rather than the name of the company organization, is preferable. Try it for yourself and see what works.

Images: Images are generally important, regardless of your product or service, or industry. But for consumer goods, they’re critical. If you haven’t included images or linked banners yet, try them and see how they improve click through rates. Try different images, and see what colors and styles people respond to best.

Layout/template: In Mailchimp, you can choose different templates and layouts. Some are better than others for your particular email content. Try a few and see which one is better.

A/B Email Testing Is Your Scientific Approach To Maximizing Conversion – But You Still Need To Be Creative

Ultimately, A/B testing serves to test ideas and quantify the results in clear black and white percentages. You can easily see what works better, and use those variables in the future to increase your open rates, click through rates and sales. It is scientific in its testing, but you need to be creative with the ideas, and think of different ways of presenting the same information and your products and services. As with everything in digital marketing, this is about trial and error – keep trying until you find something that works.

Just keep testing and playing around – every tweak can result in a significant improvement in open rates and click through rates, and even small improvements in email marketing can make you or your client hundreds or thousands of extra dollars.

Of course none of this is possible without a mailing a list – check out our guide for building mailing lists from scratch.