10 Tips for Split Testing Email Campaigns


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Marketers know there is no magic formula for an ideal email marketing campaign. The secret to an effective email campaign, whether it’s to get more web traffic, grow sales, or increase donations, is through testing and optimizing emails. If used correctly, email marketing offers a great opportunity for brands to increase subscriber satisfaction and retention, and drive results.
An effective email campaign is targeted and tested. Targeted, to ensure the message is relevant for the recipient. Tested, to ensure the message is as effective as it can be within the constraints of the campaign. With so many different variables you can test, here are the top 10 tips for split testing email campaigns:

  1. Subject lines. Subject line testing is the easiest way to increase your opens, clicks and conversions. Test different subject lines for different customer segments (e.g., use of personalization vs. non personalization, short subject lines vs. longer ones). Shorter subject lines are generally more effective (4 words/25 characters). However, what works with one segment may not work for another. Remember that your subscribers are busy and most likely have competing emails that promise to provide solutions to the challenges they’re facing. These people are just scanning their inbox subject lines. Since you only have a few seconds to grab their attention, it’s important to make your subject line as descriptive as possible and compelling enough for them to open it.

  2. Headlines. All marketing messages begin with a headline that communicates an offer or benefit. Similar to a compelling subject line, which motivates recipients to open your email, you’ll want an equally enticing headline that motivates your subscribers to read your message. Take the time to write and test various (or at least two) headlines to see which one generates the best results. Also, try changing the font size…a larger font may be more effective than a smaller font.

  3. Content/Offer. Test your content to find out what resonates with your audience. Since audiences are influenced in different ways by different types of content, identify what offers are likely to increase engagement and conversion from your subscribers (e.g., pricing, discounts, soft sell vs. hard sell, free shipping vs. discounted shipping, ebook vs. webinar, free trial vs. demo).

  4. Calls-to-Actions (CTAs). Promote engagement with the content of your email to help extend your interaction with subscribers beyond their inbox (e.g., “Register Now,” “Tell us what you think,” “Watch the video,” “Learn more,” “Download Whitepaper”). Test which offers are most successful with different segments of your audience. Offer placement is a key area to look for improvements. Try moving the call-to-action button or text link up further in the email message. Determine if this simple change increases clickthroughs or decreases action due to its location.

  5. Layout and images. Simply move elements around and test one email layout against another. Test design and navigation; make the call-to-action visible in the preview pane; and use a different image or layout to elicit different behaviors from your customers (e.g., text email vs. HTML, columns vs. a single layout, or graphics and colors). When testing layout, keep in mind that many of your subscribers probably use the preview pane feature to display email content, so be sure to use the preview pane to highlight your offer in the top four inches of the email. Also, don’t just count on images to convey your message. It is estimated that approximately 35% of email recipients block all or some of their images; and, by default, several popular webmail services and email clients, such as Google and Outlook, are set to disable images automatically. Many users do not change the default, and therefore never see your images, so be sure to include text.

  6. Days and times. Although there is no hard and fast rule, the day of the week an email is received can have a significant effect on the response. The “ideal sending time” is complex and depends on many factors such as your industry, audience demographics and message. Considering more and more people check email on mobile devices numerous times throughout the day, it is debatable whether there is a single best time to reach them. People may view your email on their mobile device while at work or on the road, but may not act on it until later that evening, or, for that matter, the next day. Is your audience located in one or more regions of the country or are they spread across several time zones? Divide your list into various segments and send on different days, and at different times, to determine the best combinations for your mailings.

  7. Landing pages. The success of a landing page mostly depends on the value and relevance of the offer. To determine which version is more effective in terms of conversions, direct people to different versions of your landing page and run an A/B or multivariate test. A/B testing is the simpler of the two approaches and involves testing one change against another, and can be used to refine various elements of your landing page (e.g., two different headlines, two different button colors, two different calls-to-action). The “winner” is determined by performance of a defined action—usually a purchase or form submission—and becomes the new control page. You can then prepare to test the winning page against another change. Once you feel comfortable performing simple A/B tests, you can get more advanced with multivariate testing. In multivariate testing many tests run concurrently and different elements on a page are tested. Instead of testing just one button color or one headline, you can test different headlines, images, button colors, calls to action, navigation, and so forth. Testing landing pages can go a long way toward improving web traffic, lead generation, subscriptions, and more.

  8. Personalization. Respond to your subscribers’ interests and needs with personalized email programs that evolve to match their needs. Personalization is limited only by the information you have on each subscriber in your mailing list or database. Capture demographic information and interests during the sign-up process, by sending surveys, or developing a preference center. Send personalized messages based on the information you gather. Deep market insight based on customer data is the key to a successful email campaign.

  9. From Field. Some email clients will only display the “From” address and not the “From” name; other email clients will only display the “From” name and not the “From” address. Use a simple “From” address and select a name that is instantly recognizable to the recipient to indicate that your message is from a credible and trusted source such as [email protected].

  10. Frequency. It’s important to find the right balance when it comes to sending email. Is your audience receptive to receiving fewer or more communications from you? To determine what contact frequency is appropriate, strive to understand subscribers’ interests in order to deliver the most relevant content to each prospect or customer at the right time. Subscribers that are opening your emails, clicking on the links learn more, and converting are the customers and subscribers you can send emails to more frequently, but only if the emails contain relevant information that is anticipated and/or will be viewed favorably by the recipients. If you normally send twice a month, test sending three times to your most engaged members since they’re the most interested in your products and services. However, if you change the frequency of your email campaigns, be sure to test the increased frequency on a small sample of your total customer base before deploying to the entire group.

Test, Analyze & Measure
Mitigate the risk of sending promotional campaigns and offers that don’t produce the results you’re seeking by testing various elements of your email marketing campaign. There are numerous ways to improve email marketing results; although some elements are easier to test than others, you’ll want to measure and analyze your results so you know what works for you and what doesn’t.

Analyze the data you capture and use it to make informed decisions. In-depth analysis of previous results and well-considered changes in email elements can significantly boost your email marketing campaign efforts.

Marianne Cellucci
Marianne Cellucci is a Sr. Online Marketing Analyst for Net Atlantic, an Email Marketing company. Marianne is a MarketingExperiments Certified Email Marketing Professional and provides email marketing consultation services to their clients. In addition to bringing a common sense approach to email marketing strategies, she has extensive knowledge of advanced techniques including segmentation and the use of lifecycle emails. She has written or co-written white papers on email marketing best practices and effective strategies for deliverability.


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