通常我們到賣場購物時，架上的產品往往不是完全補滿的，總會有或多或少的空缺。一般來說，相較於產品在供應充足的情況下，若產品相對稀缺是因為賣得很好造成的，對消費者的吸引力較大。然而，卻不是每一種產品都是相對稀缺較高，對消費者的吸引力就較大。本研究認為產品相對稀缺對消費者的吸引力，會受到產品是自我認同高相關或低相關產品，以及消費者獨特性需求的高低所影響。對於自我認同低相關產品，當相對稀缺較高時，會增加產品對消費者的吸引力；然而，對於自我認同高相關產品，當相對稀缺較高時，卻不會增加產品對消費者的吸引力，這是因為當產品相對稀缺較高時，雖會增加產品對低獨特性需求者的吸引力，但卻會降低產品對高獨特性需求者的吸引力。為了驗證本研究推導出來的三個假設，本研究先對相關構念發展量表問卷，再使用情境設計，設計了四種購物情境。在對270位受測者施測問卷後，結果發現實證結果支持本研究的假設推論。因此，對於自我認同高相關產品，應針對獨特性需求程度不同的消費者採用不同的行銷方式。最後，本研究根據研究結果，提出管理意涵以及對後續研究之建議。

When we go shopping in a marketplace, the shelves of products may not often fully supplemented. There are always some empties in some product exhibition. If a product is relatively scarce because of its ”hot sell”, it may relatively attract customers than those which are fully supplied. However, it is not always true that more scare a product is, the more attractive it may be to customers. This study hypothesized that the relative scarcity of products attracting to consumers will be affected by self-identity-relevant products and consumers' unique need. That is for less self-identity-relevant products, when relative scarcity is high, it may increase their attractiveness. However, for more self-identity-relevant products, there is no significant difference in the attractiveness regardless the degree of their relative scarcity. Because for more self-identity-relevant products, the product relative scarcity is high will increase their attractiveness to customers who have lowly unique need, but will decrease their attractiveness to customers who have highly unique need. In order to verify the hypotheses of this study, this study constructs a relevant scale questionnaire by using scenario design to design four shopping contexts. In total, 270 questionnaires were distributed to participants. The results support the hypothesis. It concludes that for more self-identity-relevant products, it is important to meet the unique needs of different consumers with different ways of marketing is important. Based on the study results, we discuss the managerial implication and suggestions for further research.