The decoy effect, also known as the attraction effect or asymmetric dominance effect, refers to the tendency of consumers to shift their preference for a sale item when presented with choices that may include one unique desirable feature even though the item may be in other ways inferior to the other choices.
For instance, a consumer wants to buy a refrigerator. They look at large units made by reputable companies but they also see a unit from on off-brand that has an unusual ice-maker. Despite the advantages of the more reputable units, they may choose the one with the unusual ice-maker because of the novelty. This is the decoy effect.