direct mail testingOne of the cornerstones of direct marketing – whether you’re using direct mail, advertising or email – is testing.

By measuring and comparing results from key elements of your program, you will be on the road to producing your most effective marketing.

Here are three points to remember on direct mail testing (or any other direct response channel).

First, understand that direct mail testing is a lot like scientific testing in that you need to isolate the component you want to test by keeping all other elements exactly the same.

In other words, if want to test two lists, make sure both lists get the exact same mail piece. If you want to test two offers, make sure the rest of the mail piece is the same and that you are mailing to same list. If you want to test a letter package vs. a self-mailer, you need to keep the offer the same and mail to the same list.

Here’s why: If you mail a self-mailer to List A and then you mail a letter package to List B, and the self-mailer generates more response, was it because of the self-mailer or the list. You don’t know because you didn’t isolate the elements.

Second, direct mail testing is not something you do just once at the beginning and then get on with your program. Testing should be an ongoing process. In your early months of a new direct marketing program, you might test more components more quickly. You might, for example, test many different lists or list segments at one time.

But as your program matures, you will begin to see winning segments emerge that together will give you what is known as a “control.” Your “control” is your best combination of list, offer, format and message.

Obviously, because the “control” is a proven success, you want to dedicate most of your budget to the “control.” But you also want to try and test new things to see if you can beat the “control” and improve your results. And this process should never stop.

Third, testing doesn’t have to be difficult or expensive. The simplest, most effective way to test is to focus on the big things first. And since the mailing list and the offer are the two most important elements in any direct marketing program, that’s where you begin.

The list is also the least expensive way to test. If you’re planning to rent 10,000 names anyway, it won’t cost you any more to rent two lists of 5,000 each. Testing offers can be a little more expensive. You will likely need to at least change text in several parts of the package – certainly on the reply form and the letter.

The most expensive item to test is the format. If, for example, you’re testing a letter package against a self-mailer, you have two separate creative assignments along with two separate print jobs. One option here would be to use one format but test different teaser copy on the outside.

But even expensive tests can be a good investment in your direct marketing program. Remember, testing gives you information that can help you produce profitable results for many years to come.


Written by Bob McCarthy

This article may be reprinted without permission as long as the article includes the following credit: Bob McCarthy is a freelance copywriter and consultant specializing in direct marketing and lead generation. His website is He can be reached at 508-473-8643 or by email at

About Bob McCarthy

Bob McCarthy is a direct response consultant and copywriter with a focus on direct mail, email and digital marketing. Bob works with B2B, B2C and Non-Profit clients. You can download his free ebook, "Making Snail Mail Work: 13 Lessons in Direct Mail Strategy."