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As a modern marketer, there are a million demands on your time and testing your email marketing campaigns may often end up relegated to the bottom of your list.

But testing doesn’t have to be time-consuming and the opportunities you can uncover to improve and optimize your results can be priceless.

In this post, I’ll break down five email tests you should run right now to get better results, plus share a few common tips for testing.

Why test?

Testing allows you to compare and contrast different elements of your email campaigns to see how they impact your subscribers’ reactions to them. You can form a hypothesis about what you think will occur, and then formulate a test and find out what really happens. For example, maybe you’re not thrilled with your email campaign click-through rates and want to increase them. We recently noticed that some of our click-through rates were plateauing, so we decided to run a few tests to see if we could boost them up. We wanted to see if we could use our Dynamic Content feature to increase the click-throughs. By using some simple segmentation and custom imagery that appealed to each individual recipient of the email, we were able to get a 13% increase in click-throughs and drive thousands of extra visitors to the content in the campaign.

This lift in click-throughs prompted us to test even more things, and we ran an A/B test of a new design of our blog subscribers email against the old one. Guess what? We got a 127% lift in click-throughs just by using a more visually appealing design.

As you can see, you can gain a ton of actionable insights from your email tests that can directly affect the performance of your campaigns. So let’s get into the 5 elements you should be testing.

5 elements of your email campaign you should be testing

Now that you understand the benefits of testing your email campaigns, let’s examine five things you can test in your emails right now to get better results:

1. Subject Lines

Subject lines are probably the most commonly tested element of emails and at Campaign Monitor we make it wicked simple to test yours through our A/B Test feature.


Some interesting things you can test in your subject lines include:

  • Length – Test short subject lines vs. longer subject lines (this is the topic of much debate in the marketing world)
  • Topic – Test two completely different topics as the subject line, to see what content is of most interest to subscribers
  • Personalization – Add personalization to identical subject lines to see if a first name greeting, for example, gets a better response.
  • Promotion/Offer – See what kind of promotion works best by offering “Free Shipping” vs. “15% Off”

2. Pre-header

Do you use pre-header in your email campaigns? Pre-header text is the first line of text in your email and can serve as the wingman to your email subject line providing more context to your subscribers of what the email is about. This is helpful in the preview pane of email browsers. Often as marketers we overlook the opportunity that pre-header presents to help improve or increase our open rate.

Some interesting things you can test in your pre-header test include:

  • Inclusion – Test including a pre-header and not including one and see if the version with the pre-header has a higher open rate.
  • Content – Include two different topics in your pre-header and see which your subscribers respond best to.

3. Day or time

One of the most common questions we get at Campaign Monitor is the what the best time or day to send an email is. And guess what? As marketers ourselves, we tell it like it is… it depends. And that’s not a cop-out. It’s the truth because every business has a different list, a different level of engagement and, of course, different content, so there isn’t a one size fits all answer. Testing the day or time you send your email is an amazing opportunity to figure out what works best for your list by looking at the change in your open or CTRs. If you always send your newsletter on Monday, try sending it on Tuesday at the same time and see what happens. Or, maybe you always send your newsletter at 9 am. What would happen if you bumped that up to 6 am?

4. Call to action

Are your calls to action getting the kind of action they deserve? When was the last time you tested yours?

Some interesting things you can test in your call-to-action tests include:

  • Copy – Test generic call-to-action copy like “Buy More” vs. more specific copy like “Get the Flare Jean Now.” In the past, we’ve done several A/B tests comparing benefit-focused copy to generic copy and each time the benefit-focused copy has increased click-through rates by about 10%.
  • Color –  Your call-to-action should complement the rest of your email, but still stand out. Test different contrasting colors to see which colors get the best response. Our friends at Unbounce declared orange to be their winner.

5. Content

We’ve all read a million times that content is king, but do you really know what content performs best in your emails?

Some interesting things you can test in your content include:

  • Length– Short form content or longer length content. Does your audience prefer short snippets with a link to read more on your site, or do they want to delve deep into longer copy?
  • Specific or Generic – At Campaign Monitor, our Dynamic Content feature enables you to display different content for different people, based on what you know about them. You can test dynamic content vs. generic content and see if you get a lift in click-throughs.
  • Positive or Negative language – You may be scratching your head when you read this one, but you can also test positivity vs. negativity in the language of your email. When you incorporate positivity into your email copy, you engage your reader’s brain in a much more powerful way, enabling them to easily understand your key messages and increasing their motivation to click-through and purchase your product. We ran a test using positive language and increased our email conversion rate by 22% using positive language so it’s definitely worth a test.

4 tips for conducting successful email A/B tests

Before you jump into the testing pool feet first, follow these four tips to set your test up for success:

  1. Know what you’re testing and why you’re testing it – This tip is common sense, but all too often as marketers, we get excited by something shiny and go running off in that direction without thinking things through. In the case of testing, make sure you slow down to speed up and figure out exactly what you want to test and what you hope to gain or learn by testing it, and, of course, how you will measure it. For example, we recently ran a personalization test in our newsletter because we wanted to learn if the personalization would improve our click-through rates. We were able to easily measure the effectiveness of the test by looking at the CTRs in the personalized version vs. the non-personalized version.
  2. The rule of two – Now that you know what you want to test and why, you need to stay focused. The golden rule of testing is to only test two variants at a time. For example, test two subject lines against each other to see which one performs better – as measured by the open rate – then you can use the top performer to send out a campaign to your list.
  3. Take action on your results – How many times have you run a test, only to do nothing with the results? Don’t let this happen to you! Have an action plan in place when you go into your test; don’t wait until afterward to make it up. For example, in the subject line test, you would naturally test the two variations to a small portion of your list, then send the winner to your full list.
  4. Test again and again – Too often as marketers we have a one and done mentality. When it comes to testing your emails, you need to have a test and test again approach because many factors can influence your tests, from time of year to the weather to the makeup of your email list. In San Francisco, workers start at one end of the Golden Gate Bridge and paint it all the way to the other end. When they get done, they turn around and paint the other direction. Use this visual reminder when you think of testing… it’s an on-going process. Campaign Monitor customer CoSchedule tested their email subject lines for three months to determine the best subject line for their Content Marketing Update email.

There you have it. Five things to test in your emails and four tips for success to get better results. Time to put your tests to the test and see what performs best.

Your turn: What A/B tests have been most successful for you? Share your success stories in the comments below!

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This blog provides general information and discussion about email marketing and related subjects. The content provided in this blog ("Content”), should not be construed as and is not intended to constitute financial, legal or tax advice. You should seek the advice of professionals prior to acting upon any information contained in the Content. All Content is provided strictly “as is” and we make no warranty or representation of any kind regarding the Content.
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