The multi-buy trick

Among the many persuasive techniques or “tricks” by supermarkets, I find this the most ridiculous. Yet, many of us may have come across or even become victim of it. As you could see from the picture, the price is 1.39 GBP for one product. The yellow tag suggests that this product is on offer and you could get two of them for just 4.50 GBP. Wait a minute! 2 for 4.50 GBP means you have to pay 2.25 GBP per product. It is actually more expensive and this is absolutely not a good deal at all. 

Supermarkets like to take advantage of using yellow tags and a so-called offer to persuade customers to buy more. This persuasive technique is called misleading inference. Supermarkets induce a misleading inference to make you think that buying two products will help you save money than just buying one. Unfortunately, customers will easily believe so if they do not think clearly. Harris (1977) found that consumers falsely assumed that juxtaposing two imperative statements in an advert would imply a causal relationship. Shimp (1978) also found that incomplete comparatives in an ad are often used by consumers to falsely infer that a product is superior to competitors. These misleading inferences can result in inflated product evaluations, beliefs, and even purchase intentions (Burke, DeSarbo, Oliver, & Robertson, 1988; Olson & Dover, 1978).

References

Burke, R. R., DeSarbo, W.S., Oliver, R. L., & Robertson, T.S. (1988). Deception by implication: An experimental investigation. Journal of Consumer Research, 14, 483-494.

Harris, R. J. (1977). Comprehension of pragmatic implications in advertising. Journal of Applied Psychology, 62, 603-608.

Olson, J. C., & Dover, P A. (1978). Cognitive effects of deceptive advertising. Journal of Marketing Research, 15(1), 29-38.

Shimp, T. A. (1978). Do incomplete comparisons mislead? Journal of Advertising Research, 18(6), 21-27.