Most marketing professionals will tell you that the key to successful direct mail is to test, test, test. (They really do say it three times. It’s that important.)

Rather than send an unproven mailer to an entire mailing list, first send it to a representative sample and watch how it performs. If it performs well, you can have a high degree of confidence that you will attain similar results when you roll it out to the rest of the mailing list.

How to split-copy-test your direct mail offer

You’re not limited to testing one version of one mailer at a time. If, for instance, you wonder which of two incentive offers is more likely to bring in business, you can find out with a split copy test.

Prepare one version of your mailer with Incentive Offer A, and the other with Incentive Offer B. Be sure that the mailers are otherwise identical. Send Offer A to every other name on a representative sample of your mailing list, and Offer B to the remaining names of the sample. Count the replies from each group. When all responses are in, it should become abundantly clear which version you should roll out to the rest of your list.

Testing shouldn’t end there. Suppose you roll out Offer B. You can set aside a representative sample of your mailing list and send them yet another offer. We’ll call it Offer C. If Offer C outperforms Offer B, you should retire B in favor of C. Next, introduce and test Offer D to a small sample. In this way, you put yourself in a position to continually discover ways to sell more while mailing to the same number of people. This can provide a way to increase profits without increasing costs.

The benefits of testing your direct mail list

You can use split testing to settle just about any question, including which headline to use, which color of ink is best and what photo works best, among other things. You can — in fact, should — also test mailing lists against one another.

Testing requires discipline. It means delaying the rollout until the facts are in. It also can mean discovering that the approach you like best isn’t the most effective. Wise direct marketers set aside personal preferences and let market behavior speak for itself. That’s what testing is all about.