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  • Writer's pictureNonprofit Learning Lab

Four Email Newsletter A/B Tests You Should Run

Updated: Jun 9, 2023

This is a guest blog and is posted with permission from Sarah Braker of Firefly Partners.

An email newsletter is one of the most common and effective ways for organizations to connect with their constituents and supporters. There are a few newsletter best practices that we recommend for every organization – predictable timing, branded templates, and directing people to your site, for example. However, there are also approaches that should be tested before you come to a final decision. This is because what works for one organization may not work for another. Using metrics such as opens, clicks, and conversions to define success, here are four newsletter elements that we recommend testing to get the best results with your audience.

One-Column vs. Two-Column

Generally speaking, the options for newsletter layout come down to one or two columns. With a two-column approach, you have the ability to include more items in less space and to position two priority content blocks at the top of your email. If a reader opens your message and doesn’t scroll at all they will at least see your two most important calls-to-action. One drawback is that even with the best planning and coding, some two-column layouts don’t render consistently across all email clients and devices. Plus, on narrow mobile devices your two-columns of content will stack, essentially becoming a one-column version.

With a one-column newsletter, you can have greater confidence that your email will appear as you intended on email clients and devices. This format also gives your subscribers the ability to easily focus on one item at a time. Be aware that the more items you have, the more scrolling is required, so content at the bottom may not get seen as often.

Clear Subject Lines vs. Clickbait

With your subject lines, you can choose to clearly explain your content or use slightly more humorous or mysterious language to try and inspire readers to open your messages. Often referred to as clickbait, the more creative subject lines might lead to opens because readers will be genuinely intrigued to learn exactly what you’re offering. On the other hand, they could be suspicious if the wording is too unclear.

Having a consistent subject line such as “March Updates from [organization]” can help subscribers get used to your messages and know exactly what they’re getting. This can also be a useful approach because it helps language like “act now” or “breaking news” stand out for moments when you need people to take action on an urgent matter. But just remember, subscribers are probably receiving dozens of newsletters each month, so creative or funny subject lines may help you stand out in a crowded inbox.

Text Links vs. Buttons

You have two options when it comes to linking to your website from your newsletter. You can use text links or buttons. Buttons are easy to spot, especially when readers are only skimming your content – but that doesn’t mean they’re always the best option. In an AWeber test, buttons started off as the more effective approach, but as the novelty wore off text links started to generate more clicks. If you start to see this trend with your A/B tests, segmentation of your audiences can come in handy. For new subscribers you might want to lean in the direction of buttons since they are just getting introduced to your style. For long-term readers you could switch to using text links.

Another strategy is to use both approaches in different ways. Buttons immediately draw attention, so they can be used for the single most important call-to-action in your newsletter such as donating or emailing an elected representative. If you want to include more than one link in a single content block, linked text works much better than having two buttons next to each other. Since you can use a mix of both elements in a single newsletter, your click rate and conversion rate (the number of clicks that lead to completed actions) will be the most valuable metrics to help you decide when and where to use which option.


Using images in your newsletters can be effective, as pictures elicit emotional responses. Powerful photos can draw readers in and graphics can connect with those who are visual learners. But images also take up space, which can lead to reader fatigue for longer newsletters. Images can also impact the orientation of your text on different devices. What appears on the side of your text on desktop will usually appear stacked on mobile. It’s essential to test every message to make sure things render correctly at every size.

Additionally, many email clients don’t automatically download images and require the subscriber to click another button to see visual elements. You can mitigate this by inserting alternative text to appear in the image space so readers who don’t download will know what you intended them to see. You’ll also want to make sure that your text makes sense without the picture beside it. For example, writing something like, “as you see here,” would confuse a reader who can’t see the photo being referenced.

How To Test

Testing various versions of your email newsletter is a long-term project. The best approach is to test one element at a time and do so for a long enough period to give you sufficient data. Three months is the minimum we recommend to run any testing plan for a newsletter, but the longer you run a test the more results you’ll have to determine a winning design. 

Our team of email marketing experts has a great deal of experience in designing and testing email templates, and we make it easy for nonprofit staff to duplicate templates and insert content once a final design has been selected. If you want to learn more, or have a newsletter project in mind, reach out to us today.


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