Prior to 1920, more than one-third of the general magazine advertisements featured a return coupon. These coupons were mainly used as a means of distributing free product samples to potential users. The advertiser was gratified when a particular piece of copy elicited a huge number of coupon requests.
Stanley Resor of J. Walter Thompson was one of the first to commission a study looking at the rates of coupon returns and advertising effectiveness. Resor even hired Dr. John B. Watson, the famous behaviorist, in 1921 as part of his effort to find out why people bought a particular product. For a long period of time the coupon method was viewed as a means of sampling the brand and testing the efficiency of the copy. Of course, since the advertisement had already been published, this was essentially a post-test assessment of the copy. There were also attempts to evaluate different copy treatments based on the cost per coupon returned.
During the Great Depression, coupon usage was at its height and provided an excellent opportunity for market research. In 1930, Harold Rudolph published the book Four Million Inquiries from Magazine Advertising, which was based on studying coupon returns. Subsequently, Daniel Starch compiled an analysis of millions of coupon responses.
Using coupon response as a means to test copy had the benefit of being based on actual consumer behavior instead of mere intentions. However, it had some severe limitations including the inconsistent usage of coupons by certain customers. A survey by the manufacturer of Ipana toothpaste (Bristol-Myers Co.) discovered that the great majority of coupons were returned by habitual clippers, many of whom were already users of the product. Also, certain categories of coupons (e.g., those for free samples, those that required a nominal charge for a sample, those that requested additional information, those that offered mail-order sales, etc.) yielded different patterns of responses.
As it became increasingly clear that analyses of coupon returns were not adequate to test the quality of the advertisement or the impact it had on potential buyers, what has been called the Opinion Ratings method, where responses were sought from potential users of the advertised product, took hold. This method had the additional advantage of being able to obtain feedback from potential customers before incurring any major media expense. Its proponents argued that the results were valid as it could analyze the opinions of likely users instead of random samples of audiences who may or may not be prospects for the product being advertised. However, it was soon found that this approach had its own limitations; it was essentially comparitive in nature (between two or more alternatives), and while people might be able to rate one ad over another for believability or even interest, there was doubt that they could rate them for effectiveness. Consequently the Opinion Ratings approach fell into disfavor in the early 1930s. However, variations of this approach continue today and it may well be credited with being the forerunner of many current focus groups.
A seminal development in copy testing was the 1923 publication of a paper titled “Testing the Effectiveness of Advertisements” in the Harvard Business Review by Daniel Starch. Among other things, Starch proposed that in order to be effective, an advertisement must a) attract attention, b) arouse interest, c) be believable, d) be memorable, and, finally, e) produce a response.