Direct Response Advertising (i.e. Ads with telephone numbers) on television is growing. It is in the interests of all to try to ensure the medium is used with maximum efficiency. This study merges two sets of data, the audience to DRTV commercials and telephone response data which can then be cross-analysed against various criteria to see what will produce the best response rate. The factors examined are several but include such items as the best time of day to advertise, the best length of the commercial, whether to have a voice-over of the telephone number and so on. The results described below should enhance the general understanding of DRTV and enable those especially newer to the medium to obtain more from their T.V. expenditure.