Persuasive Advertising - J. Scott Armstrong [134]
Power words can sometimes change the way people look at a product. In particular, this has been noted for the use of the word “free.” Instead of thinking about costs and benefits, it leads people to think only about benefits.
It is important that the power words fit the product. For example, “improved” is not a good word to apply to beer, which relies on traditional tastes. A Bernbach ad for Utica Club said, “Our beer is 50 years behind the times (and we’re proud of it).”
Power words might come across as being pushy. Thus, the use of power words seems more relevant for low-involvement products and when audio is used, although the evidence on this point is sparse—note that I am hedging.
Evidence on the effects of power words
A meta-analysis found 16 studies on power words, drawn from legal cases. These involved mostly oral arguments in high-involvement situations. The studies compared arguments that used powerful words and expressions with those that used hedges and qualifiers. Hedges and qualifiers were less credible in 14 of the 15 comparisons with one tie, and less persuasive in four of the five comparisons with one tie (Burrell and Koper 1998).
Here is a lab experiment on the use of the word “free.” A choice of a Lindt chocolate truffle at 15 cents or a Hershey’s Kiss at 1 cent was offered to 398 subjects. Of those making a choice, 27 percent chose a Kiss. When the price of each was reduced by one cent, so that the Kiss was “free,” 69 percent chose a Kiss (Shampanier, Mazar, and Ariely 2007). Talk about power.
A lab experiment used modified print ads for beer, airlines, and analgesics to include (1) no power words, (2) power words in the headline only, or (3) power words in the headline and text. Some power words were designed to fit the product; some were not. The ads were presented to 304 subjects. Ads with power words that fit the product and were not overused had substantially higher purchase intentions than ads without power words (Kover and James 1993).
Power words can be problematic for high-involvement products when the advertiser wants the customer to think about an offer. This was supported by a lab experiment that dealt with written communications (Gibbons, Busch, and Bradac 1991).
Our analysis of quasi-experimental data supports the use of power words for low-involvement products:
Power words increased recall for low-involvement products. Our WAPB analyses found 20 pairs in which one ad used power words and the other did not. Recall for the ads with power words was 1.10 times better than for the other ads.
7.3.3. Use active rather than passive voice, unless the subject of the sentence is obvious
The advice to use active-voice sentences is so common that we might wonder why the passive voice exists. Passive voice often leads to less precise writing. For example, the passive form, “Research was conducted on the brand and it showed favorable results,” does not tell who conducted the research. Active voice seems more likely to lead the writer to be clear about who did what, such as, “Ajax laboratories conducted research that showed favorable results.”
Active voice often helps reduce the number of words and to produce more rhythmic copy. Consider these sentences in which the active voice has fewer words. Passive: “A larger size and great taste are two benefits Pepto-Bismol offers.” Active: “Pepto-Bismol comes in a larger size and tastes great” (Antin 1993).
The active voice can aid emphasis to the subject of a sentence. For example, it might be used to emphasize a brand name. On the other hand, passive voice can aid clarity if it can build upon previous text.
Evidence on effects of active versus passive voice
Based on their research review, Anderson and Davison (1988) concluded when earlier text has alerted the reader about what will follow, passive sentences require less time to read and are better understood than active sentences.
In a lab experiment, fictitious slogans for four product categories were shown to 96 subjects. Slogans with active