Persuasive Advertising - J. Scott Armstrong [177]
Long copy is especially important during the early stages of a product’s life cycle—the stages in which customers are most in need of information. An analysis of 62 full-page print ads found that the average copy length for products in their introductory phase was over twice that of products in the growth phase, almost three times that of products in the mature phase, and almost seven times that of products in the declining stage (Dodge and Fullerton 1984).
Even if customers for low-involvement products do not read the entire text of the long copy, they often assume that long copy is providing good reasons for buying the product. For example, in the early 1900s, Claude Hopkins wrote a five-page solid-text advertisement for Schlitz beer; his ad was said to have helped move Schlitz from fifth to first place in sales.
Many experts have claimed that long text is persuasive. King Gillette, the inventor of the safety razor in 1888, said that you cannot have too much copy as long as it is honest and to the point. Henry Ford agreed. So did David Ogilvy; one of his Rolls-Royce ads had 1,400 words.
Beware: long copy that goes beyond what is needed will increase the advertiser’s media costs and waste customers’ time. Furthermore, needless words are likely to detract from strong arguments. So it is advisable to include all relevant information in few words. This is not easy advice to follow. In 1657, Blaise Pascal sent a letter saying, “The present letter is a very long one, simply beause I had no leisure to make it shorter.”
Evidence on the effects of long copy
In a lab experiment, print ads for eight products were randomly presented to 164 German subjects. For each product, one version had text while the other version did not. Subjects were allowed only three seconds, which was clearly an insufficient time to read each ad. Nevertheless, they rated the ads with text as more credible (Meyer-Hentschel 1984).
Turning to non-experimental evidence, in the Direct Marketing Association’s 1991 Echo Award competition, the 99 direct-mail pieces that exceeded seven pages drew an average of about 25 percent more consumer inquires than did the 94 pieces that were seven pages or fewer (Woodside, Beretich, and Lauricella 1993).
Customers often will not bother to read long copy for low-involvement goods, as shown in an analysis of 1,080 ads in Life magazine—readership was lower for ads with more than 50 words. However, this was not true for high-involvement utility products (Diamond 1968). An analysis of 539 ads from Iron Age , a trade magazine for the iron and steel industry, found that ads with more than 100 words received higher scores for “started to read,” “aroused interest,” “read half or more,” and “kept customers sold” (Soley 1986). A McGraw-Hill study covering nearly 3,600 ads, presumably for business-to-business markets, found that longer ads (300 or more words) increased awareness, led to more interest, and improved consumer preference for the brand (Donath 1982).
9.3.3. Repeat the main message at the end of the ad
The message “reinforcer” used at the end of an ad should be short, memorable, and relevant to the product. The principle is often used. For example, in our WAPB analysis, 64 percent of the print ads repeated the main message at the end.
Evidence on effects of repeating the main message at the end of an ad
Our quasi-experimental analysis of print ads supports this principle:
Print ads with message repetition at the end improved recall and persuasion. Our analysis of quasi-experimental data from WAPB found 52 pairs of print ads in which one of the ads used a short message reinforcer at the end while the other did not. For example, an ad for Monroe car shock absorbers that ended with the repeat claim ‘the bump stops here” had much better recall than another Monroe car shock ad that did not repeat the main message at the end. Recall for ads with late repetition of the message was 1.14 times better than for the other ads.
We analyzed non-experimental data on print ads