沉沒成本常影響消費者升級和購買新產品的意願，然而，沉沒成本對升級與購買新產品意願的影響可能受品牌與顧客之間的關係所干擾。作者執行兩個實驗來驗證本主張，結果顯示沉沒成本效果受到品牌與顧客之間的關係所干擾；此外，這樣的干擾效果不僅存在於品牌與顧客之間的關係型式，亦存在於事先無關任務的人際關係促發。具體而言，沉沒成本效果僅在交易型關係才會顯現，但在共有型關係時就不顯著。最後，作者討論本研究對理論與實務的一些重要影響與貢獻。

Sunk costs often affect consumers’ willingness to upgrade to or purchase a new product. However, these decisions might be not only influenced by sunk costs but also moderated by the relationship the consumer has with the brand or by interpersonal relationships primed by a different task. Two experiments examine these propositions, and the results show that the sunk cost effect is moderated by the brand–customer relationship and a salient interpersonal relationship type primed by an unrelated task in advance. Specifically, the sunk cost effect is pronounced only in exchange relationships; it does not emerge in communal relationships. This article concludes with a discussion of some key theoretical and practical implications.