When marketers design websites, draft emails and write calls to action, they often create by intuition. But rather than relying on creative assumptions, strong marketers put their best ideas to the test. Split-testing or a/b testing direct mail marketing content is the only way to truly know what will make people convert.

With emails, one of the most tested variables is a different subject line. Social media ad managers would often put to test the banner design. While a/b testing direct mail may take a few more steps than split-testing digital marketing, it is just as important. You can use a/b testing to guide your direct mail decisions and improve the overall marketing campaign results. It will just take a little planning.

In this post, we’re going to walk you through 3 ways to split-test direct mail. (You can find out exactly how to run a direct mail a/b test using Inkit here.)

3 Split Test Mailer Ideas for Your Next Direct Mail Campaign

Running effective a/b experimentation on direct mail doesn’t have to be very complicated. Here are a few traditional direct mail examples to split test your next direct mail testing strategy:

A/B Direct Mail Test #1: Single variable split-test

This is what most people think of when talking about split-tests. In a single variable direct mail test, you create one mailer, duplicate it, and edit one single item on the b-copy. In this type of split-test, everything except for the test variable needs to remain identical. You then randomize and split your direct mailing list so that one version goes to half your audience and the other version to the other half. In most cases, a single variable direct mail test is the ideal method because it makes it very clear why your audience reacted a certain way. If you were to test two completely different postcards, on the contrary, which elements inspired action would not be evident.

When deciding which variable to split-test in direct mail, consider:

• Different offers, such as a discount + free shipping vs. greater total discount amount or a discount vs. a sign-on bonus or free gift
• Different presentations of the same offer, such as different expressions of the same discount (such as dollars off vs. percent saved), call-to-action copy, headline copy and eye catching design
• Various direct mail formats (marketing postcard sizes)

For inspiration, review some of the proven postcard design and copy best practices. If you want your direct mail piece to grab your customers’ attention as soon as they open a mailbox, experiment with different postcard sizes, colors and graphics of your postcards, as well as an envelope (or a lack of one) and personalization approach.  

Click here to learn how to split-test postcards with Inkit.

A/B Direct Mail Test #2: Existing/prior campaign control group test

In this type of test, your “A” mailer is one that you have sent before. You will create a new “B” postcard to test against it. “B” can be completely different than A, with many variables, or you may still decide to test a single variable for better clarity in results. Like in the previous test method, you would split your direct mail list in half, sending one group the control postcard and one group the new postcard. This is a method to continually improve an on-going direct mail campaign (like an onboarding or ‘welcoming a new customer’ campaign, where you get a continuous influx of new contacts into your CRM list).

Remember to make sure that each half of your direct mail list that’s being tested receives only one type of a mailer (“A” or “B” only) during the test period, and is not subjected to multiple direct mail or digital campaigns at the same time. Otherwise, you won’t be able to properly track the performance.

Pro tip: if you automate direct mail using triggers, consider running a control test from time to time to in order consistently enhance campaign performance as your audience changes and grows.

Here are a few creative ideas for direct mail control group tests:

• Altered redemption periods (will you receive better or worse conversion with a longer or shorter redemption period?)
• 50% discount or “two for the price of one”?
• Design
• Images (photographs vs. graphics is a common one)
• Color scheme
• Headlines
• CTA verbiage
• The timing or trigger

A/B Direct Mail Test #3: Testing the medium

This style of a/b test is perhaps the best way to answer the question: is direct mail worth it?

Many people reading this blog are e-commerce B2C or services B2B marketers who work primarily in digital channels. You might just need to know whether, and how much, direct mail will boost your digital campaigns. In this type of test, you’re not really split-testing direct mail pieces. You’re split-testing two digital campaigns, one that includes direct mail and one that doesn’t.

In a direct mail medium test, your entire audience would receive the digital elements of a campaign sequence. But you would edit the workflow for half of your audience so that they also receive a postcard, or another piece of direct mail. Then, compare how the inclusion of direct mail effected campaign performance. When evaluating results, look not only at response  and conversion rates, but also total ROI (since direct mail isn’t free to send) and the impact to engagement.

Another way to test direct mail as a medium is to move an email promotion into direct mail format, as NatureBox did using Inkit’s direct mail software.

How to Track Direct Mail A/B Test Results

Direct mail campaigns usually have good open and response rates compared to email marketing. In order to run effective direct mail testing strategies, of course you need a way to effectively measure and track campaign performance. There are several ways to track direct mail results, including:

• Unique URL: Create a unique landing page for each test version (with and without a direct mail as an additional marketing channel).
• Unique discount code: Use a unique discount code for each postcard test copy.
• Unique text shortcode: Write a special SMS shortcode as your CTA for each test version.
• Unique QR code: Use a different QR code for each iteration.
• Unique phone number: While this is not as common with digitally-integrated postcard campaigns, this is another tracking option that may work depending on the nature of your direct mail marketing campaign.

Automate Direct Mail Testing Strategy to Continually Test and Improve Postcards

One of the great things about modern direct mail is that you have an opportunity to continually learn about your customers and add this information to your database without running formal split-tests.

Wait? Wasn’t this entire post about the benefits of direct mail split-tests?

Yes, it was. And we still think running a/b split-tests on your direct mail is key. However, when you automate direct mail using a platform like Inkit in lockstep with your CRM, in a way you are always testing direct mail. When you automate direct mail (triggering it from your CRM and syncing campaign performance), you will have your finger on the pulse of your customers and can continue to refine direct mail campaigns based on consumer actions every day.

Got any questions about making direct mail A/B testing or direct mail automation work for your business? Contact us today. We’re always happy to help find solutions!