There are many ad specialty products that can be mailed. According to PPAI, promotional products, used in conjunction with a sales letter or as an incentive to respond, can make a significant difference in direct mail response rates. In fact, adding a promotional product can increase the response rate by as much as 50%! And, the use of a promotional product as an incentive to respond can generate four times as many responses than a sales letter alone. Further, the use of a promotional product as an incentive to respond can reduce the cost per response by as much as 67%! This is welcome news amid discouraging typical response rates of less than 2%.