key

Device which enables advertiser to identify source of inquiry as when a coupon has an unobtrusive key printed in the corner (e.g. DM5 meaning fifth insertion in the Daily Mail). Keys can be included in the address. A different person’s name can be used in each journal, or there can be a variation in the address such as 11a, 11b, 11c. By means of keys it is possible to calculate the cost-per-reply by dividing the cost of the space by the number of enquiries. Similarly, cost per conversion to sales can be calculated.

The expert's thoughts on direct response - growth hacking - performance-based marketing activities - DIRECT MARKETING