As online group buying (OGB) businesses increasingly face strong competition, understanding the beliefs, attitudes, and behaviors of their customers is critical. Hence, the purpose of this study is to understand why customers choose one OGB vendor over others. By extending the transaction cost economics (TCE) theory, we explain OGB customers’ purchase behavior. We conducted a two-stage online survey. The first survey (T₁) captured the perceptions of the respondents before making a purchase (i.e., purchase intention and its antecedents, namely unpredictability, trust, customizability, and frequency of OGB use). In the second stage (T₂), we collected responses from the participants of the first study who committed at least one purchase in the last month. The second survey collected responses about the frequency of OGB use, purchase behavior, and online customer review (OCR). Data were analyzed with partial-least-square-based structural equation modelling technique (PLS-SEM). Results suggest that unpredictability, trust, and customizability influence purchase intention and are influenced by the frequency of OGB use. In addition, customizability decreases unpredictability. Finally, in seeking an answer to how to convert potential customers into actual customers, we found that OCR is a moderator of the relationship between purchase intention and purchase behavior. The findings from the longitudinal study extend TCE theory in electronic markets by capturing the OGB dynamics (i.e., antecedents and effects), the mediating effects (i.e., purchase intention) and the moderating effect (i.e., OCR) in a robust nomological relationship.

随着在线团购 (OGB) 企业日益面临激烈的竞争，了解客户的信念、态度和行为至关重要。因此，本研究的目的是了解客户为什么选择一个 OGB 供应商而不是其他供应商。通过扩展交易成本经济学 (TCE) 理论，我们解释了 OGB 客户的购买行为。我们进行了一个两阶段的在线调查。第一项调查 (T ₁ ) 捕捉了受访者在购买前的看法（即购买意图及其前因，即不可预测性、信任、可定制性和 OGB 使用频率）。在第二阶段（T ₂)，我们收集了第一项研究的参与者的反馈，这些参与者在上个月至少购买了一次。第二项调查收集了有关 OGB 使用频率、购买行为和在线客户评论 (OCR) 的回复。使用基于偏最小二乘法的结构方程建模技术 (PLS-SEM) 分析数据。结果表明，不可预测性、信任和可定制性影响购买意愿，并受 OGB 使用频率的影响。此外，可定制性降低了不可预测性。最后，在寻求如何将潜在客户转化为实际客户的答案时，我们发现 OCR 是购买意愿和购买行为之间关系的调节器。纵向研究的结果通过捕捉 OGB 动态（即，