Want to improve response rates for your next direct mail marketing campaign? Consider including a gift with the package.

Researchers at the University of Bonn in Germany found that charitable donations rose dramatically when solicitation letters included a “gift” for the recipient.

In the study, approximately 10,000 solicitation letters were sent to potential donors on behalf of a charity. A third contained just a letter, explaining how the money would be used to help children in need. Another third contained the letter plus a small gift — a full-color postcard containing a picture drawn by one of the children the organization was helping. The final third contained the letter plus a more substantial gift — four of these postcards, each with a different drawing.

The letters sent with no gift elicited a 12% response. The letters with the simple, one-postcard gift received a 14% response. And the letters with the larger, four-postcard gift received a 21% response.

The sum of donations followed much the same pattern, with an 11% higher average donation size among those who received the small gift over those who did not receive a gift, and a 62% higher average donation size among those who received the larger gift over those who received no gift at all.

While the study cited here dealt with nonprofits, similar results may be possible with for-profit companies, too, thanks to the law of reciprocity.

Reciprocity, the researchers explained, is a feeling that “we are obligated to the future repayment of favors, gifts, invitations, and the like.” They concluded that reciprocity accounted for the vast majority of the differences they saw in their results.

Of course, gifts alone are no guarantee of direct mail success. “If we had included gifts which were completely unrelated to the purpose of the solicitation or which were considered inappropriate,” the researchers wrote, “the response might have been weaker or even negative.” So, in other words, choose your gifts wisely. Or better yet, get some help in choosing an appropriate gift, from a direct mail expert like the staff at our printing firm.