Despite the extensive research on loyalty, academic discussions on simple and effective loyalty indices are surprisingly scarce. One of the few suggestions for loyalty indices is the net promoter score (NPS). Approximately two-thirds of Fortune 1000 companies currently use this index due to its overwhelming simplicity. However, scholars have criticized NPS for being inferior to other loyalty indices. Accordingly, scholars have mainly used Likert scales that cannot compare products/services using a single question and are subject to a response bias due to cultural differences. To fill this gap, we address the following four main criticisms of NPS: First, its advantages over the Likert scale of preferences and recommendation and purchase intentions are unproven; second, it cannot compare a competing product or service using a single question; third, its threshold setting is subjective; and fourth, it suffers from a cultural response bias tendency. This study asks the following research question: “Is brand selection superior to Likert scales in explaining sales performance?” To form a generalized conclusion, we examine 100 brands selected from 20 industries in the US market. The results of randomized controlled trials prove the superiority of selection over scale. Thus, brand selection should be emphasized to measure brand loyalty.

尽管对忠诚度进行了广泛的研究，但关于简单有效的忠诚度指数的学术讨论却出奇地少。忠诚度指数的少数建议之一是净推荐值 (NPS)。由于该指数极其简单，目前约有三分之二的财富 1000 强公司使用该指数。然而，学者们批评 NPS 不如其他忠诚指数。因此，学者们主要使用李克特量表，该量表无法使用单个问题来比较产品/服务，并且由于文化差异而容易出现反应偏差。为了填补这一空白，我们解决了对 NPS 的以下四个主要批评：首先，它相对于李克特偏好量表以及推荐和购买意图的优势尚未得到证实；其次，它无法使用单个问题来比较竞争产品或服务；第三，其阈值设定具有主观性；第四，存在文化反应偏差倾向。本研究提出以下研究问题：“品牌选择在解释销售业绩方面是否优于李克特量表？” 为了得出概括性结论，我们研究了从美国市场 20 个行业中选出的 100 个品牌。随机对照试验的结果证明了选择相对于规模的优越性。因此，应重视品牌选择来衡量品牌忠诚度。