Direct Mail Testing Strategy for Marketing Success

You would be forgiven for thinking that direct mail is a simple and uncomplicated marketing strategy because, for the most part, that's what it is. In comparison to various types of digital marketing platforms, direct mail is almost effortless.

However, there are subtle nuances of your direct mail campaign that require a little extra attention if you want your campaign to perform. We are referring to the smaller details that aren't quite make or break but could make the difference between a staggeringly successful campaign or a mediocre one. 

But there are a lot of decisions to make regarding a lot of details. 

For example, the flyer may look vibrant and attention-grabbing, but does it lend itself to the brand messaging? Or maybe your copy is engaging and fun, but is it possibly a little too familiar and casual for the audience in question? Even the smaller details, like your choice of font or type or type of paper, make a difference, as will the size of the mail piece.

Faced with an overwhelming amount of options, how can you possibly know which decisions will lead to a truly successful campaign and which won't? Ultimately, the proof lies with the results, and you can't know for sure until you try out the different techniques by actually sending them out.

Why Is Testing Important?

For the most part, direct mail is a numbers game. Being so budget friendly - with such a high reach for a comparatively low spend - the chances of a healthy ROI are quite high as you can reach a huge audience for relatively little spend, in comparison to other forms of direct advertising.

Let’s not lose sight of that fact. Even without lots of testing in place, the results will almost certainly justify the campaign spend on some level. There is a reason why direct mail is such a stalwart in the world of advertising and marketing, after all. 

However, you should look at the notion of testing as a way to achieve optimal results. Think of it as a chisel to your sculpture, chipping away at the outer pieces until you reach a thing of beauty: a carefully crafted masterpiece that has taken a potentially ‘adequate’ direct mail campaign and transformed it into something magnificent.

It is that magnificence that we hope to steer you towards throughout this article: the Taradel guide to direct mail testing and best practices that, when applied, can almost guarantee optimal results for your campaigns.

But first, there are some steps you may need to consider in order to prepare your direct mail campaigns for the actual testing relating to tracking the results. 

Ensure Trackability

Direct mail has always been quite difficult to measure - again, in comparison to digital marketing platforms, at least. 

Mail tends to have a longer response life than other methods, often spending weeks or months at the address before any action is taken, if any. Also, unless there is a dedicated call to action through a unique URL, QR code, or phone number, measuring the metrics can be quite challenging.

Either way, if you are going to test different direct variables and make subtle tweaks here and there, you need to be able to identify which variables are worth sticking with (and ultimately scaling) and which ones need to be scrapped.

To do so, there are a few steps you can take to allow for actual tracking. Let’s take a look.

Use Custom URLs

You can better gauge the response rate of direct mail campaigns with the inclusion of dedicated custom URLs into the CTA of your mail. Custom URLs are a great tool for tracking direct mail responses. By creating unique, dedicated web addresses for your direct mail campaigns, you can easily monitor who visits your site by looking at the stats for each landing page.

Use Custom Toll-Free Numbers

The exact same principle as above - use dedicated toll-free inbound numbers for each campaign in order to identify and measure split testing. Separate toll-free numbers can be analyzed by looking at the CDR (call delivery report) provided by your provider. 

Create QR Codes

Scanning a QR code allows for a much quicker and more convenient user experience than typing in a lengthy URL. Even when URLs are shortened to their briefest form, QR codes maintain the advantage of retaining your customer's attention. Plus, they take up very little room on your direct mail pieces. 

You can create separate QR codes for each direct mail piece you are testing and measure the stats on your back end to determine the best performance.

Issue Coupon Codes

While QR codes and custom URLs are a good way to monitor the response rate of your direct mail campaign, coupon codes will help identify customers who have actually made a purchase. By tracking the number of submitted coupon codes, you can measure the conversions precisely.

By using any (or all) of these methods, you can split-test your campaign with dedicated, unique reference points that will allow you to measure which strategies are performing and which aren't.

So, let's say you decide to test two different creatives and use a unique URL to test the results; one is quite vibrant and playful in nature, with loud colors and bold, proud fonts, and the other with a more toned-down subdued feel. After a set period of time (let's say five business days), you can look at the stats for each URL to determine which received the highest number of visitors.

Direct Mail Testing Strategies

With your tracking system determined and enabled, let’s take a look at the different split-testing variables you can use. 

1) Try Different Sizes

The very first thing you could experiment with is the various formats, sizes, and shapes of direct mail pieces. In doing so, you will determine which ones capture your audience's attention most effectively. 

For instance, you could explore the impact of comparing postcards to letters or pitting a tri-fold brochure against a booklet. Taradel’s EDDM mailer sizes range from 4.25x11 to several different sizes up to 11x17, for example. Alternatively, our personalized mail sizes range from 4x6 to 6x11.

Depending on various factors such as audience, brand messaging, and desired outcome, each mailer size is possibly more likely to resonate more with one audience type than another. 

2) Test the Audience

The heart of any direct mail testing strategy is the audience you are aiming to engage. The type of list you use for a direct mail run can make or break that entire campaign; it's as simple as that. 

Through testing, you should aim to divide your recipients into separate segments and then analyze the data to improve your campaign.

For instance, by using our demographic heatmap, you can reach specific audiences in certain areas through highly refined targeting. Through one test, you could target homeowners with a household income range of $25-$75k with a median age range of 35-55. Through another, you could target renters instead of homeowners. 

Alternatively, you could target homeowners but split the testing between age groups or length of residence, for example. 

The parameters are endless, with a multitude of variables that can be fine-tuned through testing until you find the perfect audience.

3) Run Different Offers

At the risk of stating the obvious, the quality of your product, offer, or service really matters. There is a common misconception (albeit among a minority) that the primary driver behind your sales, subscriptions, or client acquisition is the creative and copy.

The fact is, no matter how stunning your design or how engaging your copy may be, it is the offer that leads to sales and is the main reason for recipients either acting on your mailer or throwing it to one side. 

The more compelling the offer, the better your response rates will be. Through testing, you have the luxury to run two similarly-priced offers against each other to see which one resonates with your audience. 

For example, your current promotion might include a healthy discount for your audience - but a two-for-one offer might perform better. 

There are many different tactics you can deploy in incentivizing your product or service, but the only way to know which one performs the most is to split-test as many as possible.

4) Tone of Voice & Copy

The chances are you know your audience very well and are aware of the type of language that resonates with them. If you are using targeted lists through personalized mail, you can create compelling copy that speaks to the audience in question based on various factors such as interests and professions.

However, if you are running a more generic campaign such as Every Door Direct Mail, you will need to create copy that resonates with a far broader range of people. 

To do so, one idea is to compose a split test campaign comprising different copy styles in order to determine which produces the best results. For example, you could try a jovial tone of voice with short, ‘punchy’ messaging or possibly even a little mild humor. By the same token, another set of mailers could speak in a more polished, professional tone. 

5) Testing Your CTA

Often overlooked, the CTA is one aspect of your direct mail that could be tested for optimal results. Most direct mail flyers and letters go with the tried and tested “Call Now” as a call to action, but through experimentation, you can create something that might just contribute towards improved results.

A few alternatives might include (but are certainly not limited to) the following:

Discover More Today - to intrigue and evoke curiosity in the recipient.

Join Our Community - Instead of directly asking for the business, this angle evokes inclusivity (in a subliminal way, at least) and being ‘part of something.’

Dive into the Details - for a more playful angle on the usual ‘find out more’ CTA.

All you are doing here is setting up a controlled environment to gauge how your audience interacts with the different CTAs. After you've allowed all versions to run their course for a predetermined amount of time, analyze the stats and pick a winner. 

Other options would be to try different colors, fonts, and sizes of CTA. It's all about continually fine-tuning until you hit the sweet spot that gives you the best results. 

How Many Variables Should You Test?

With so many variables in play here, things can get very complicated very quickly. A test batch consisting of several variations of variables will be extremely difficult to analyze post-test, owing to the sheer number of potential permutations involved.

The simplest method is a regular, uncomplicated A/B test, with one variable split straight down the middle. This method essentially creates two versions of your mailer, both of which are identical except for one distinct change (such as the CTA, for example). 

With the split complete, you simply send one version to one group and the other version to another group. Then, it's a matter of waiting for responses and analyzing the outcomes.

If you are testing only one variable - such as the CTA - you can split this as many times as you wish. Five identical mailers, each with different CTA’s, to five different groups, for example. 

After analyzing results, you now have your ‘control’ CTA - the call to action that you will be using going forward. At that point, if you wish, you can begin a whole new set of testing by starting again with a new variable, such as the audience type or the copy style. 

Then, repeat the process until you have your ‘control’ on each one.

Always Test the Same Audience

You are almost certainly aware of this already, but we shall point it out, just to be safe: you should never test different variables to different audience types. 

If you are testing one variable to a Gen Z audience and then a completely different variable to millennials, for example, the results will tell you nothing useful. 

The audience should always be identical in terms of demographics, psychographics, and geographics. Run an even split to the same number of people in the same categories.

Feel free to test different audiences with the exact same direct mail piece, of course. Audience testing is a huge part of this process, after all, and you can split-test as many different audience types as you like - but always make sure the mailer is the same when testing variables in the actual audience. 

How Many Mailers Should You Test?

So, how many actual mail pieces should you send out in order to test the different variables? To answer that question, we need to consider the ‘law of averages’ to some degree. Essentially, the main challenge is ensuring that the sample size is sufficient to produce reliable results without being influenced by random factors.

A common mistake is underestimating the necessary sample size, which may lead to inconclusive or misleading outcomes. In other words, a few hundred mailers simply won't cut it. To test effectively, you really need to commit to it.

A small sample size might not provide a clear picture of the audience's response, as there are simply too many random factors that can falsely influence a test. You need to take those random factors out of the equation by avoiding small test batches.

A larger sample size reduces the impact of random variations and provides a more stable representation of results.

In terms of specifics, you should be looking at a test batch of at least 10% of your intended volume for the entire campaign. So, if you are planning to send out 100,000 mailers total,  you should allow somewhere in the region of 10,000 as a test batch.

However, if you're assessing multiple variables (and not just one or two), you will need to consider an even larger sample size.

Keep It Simple

At the end of the day, direct mail is mostly a numbers game. If you send enough mailers out, you are probably going to see quite reasonable results as a worst-case scenario. 

That said, a little split testing will go a long way to fine-tuning your offer into something quite special. Keep it simple, and aim to A/B split test different variables until you find your ‘control’ with each one.

Then, move on to the next group of testing to find your new control with a new variable. Eventually, each aspect of your mail piece will consist of ‘the perfect control’ and should lead to improved results.

Bottom Line

Again, direct mail is, in essence, quite a simple endeavor with a straightforward ethos: if you target enough people, you are going to see a response. With the cost of direct mail being so budget-friendly, the number of responses will almost certainly justify the campaign spend.

However, as with anything relating to advertising, the devil is in the details, and you need to pay close attention to the subtle intricacies of the messaging. This involves comprehensively testing variables, ensuring trackability, and having a firm grasp of your target audience. 

Looking for professional guidance on optimizing your split testing? Connect with our direct mail specialists at Taradel, and let us create a tailor-made direct mail campaign today.