隨著網路平台與社群媒體的發展，企業逐漸採用一般通路與團購通路並行的雙通路銷售模式。團購通路雖可透過價格優惠與需求聚集吸引消費者，但也可能造成一般通路需求移轉，並受到成團門檻限制，使團購需求未必能轉換為實際成交量。因此，零售商在導入團購通路時，必須同時考量一般通路價格、團購通路價格與團購成功門檻之決策。 既有文獻多分別探討團購價格、團購門檻、雙通路定價或社群互動，較少同時將零售商定價決策、成團門檻、團購主形成與消費者社群接觸納入同一模型。基於此，本研究建立一個雙通路社群團購決策模型，探討零售商如何在一般通路與團購通路並存下，設定最佳一般通路價格、團購通路價格與團購成功門檻，以最大化其期望利潤。 本研究採用單期 Stackelberg 賽局架構，零售商先決定價格與門檻，消費者再根據推廣能力、社群規模、推廣回報與推廣成本判斷是否成為團購主。未成為團購主之消費者，可能因受到團購主接觸而成為跟隨消費者，或因未被接觸而成為獨立消費者；若同時受到多位團購主接觸，則透過多項羅吉特模型決定其最終歸屬。最後，消費者依通路效用選擇一般通路、團購通路或不購買，並在 all-or-nothing 成團機制下判斷團購是否成立。透過此模型，本研究可分析社群團購情境下零售商定價、成團門檻、消費者角色形成與通路需求之關係，並作為後續數值分析與敏感度分析之基礎。;The growth of online platforms and social media has encouraged firms to adopt dual-channel selling strategies that combine a regular sales channel with a group-buying channel. Group buying can stimulate demand through price discounts and demand aggregation， but it may also divert consumers from the regular channel. Since group buying is subject to a threshold， potential group-buying demand may not always be realized as actual sales. Retailers therefore need to jointly determine the regular-channel price， the group-buying price， and the group-buying threshold. A dual-channel social group-buying decision model is developed to analyze the retailer’s optimal pricing and threshold decisions. The model is formulated as a Stackelberg game， in which the retailer first determines the two channel prices and the threshold. Consumers then decide whether to become group leaders based on their promotional ability， social network size， promotional reward， and promotion cost. Non-leader consumers may become followers through social contact or remain independent consumers. If a consumer is contacted by multiple group leaders， a multinomial logit model is used to determine the final affiliation. Consumers then choose from the regular channel， the group-buying channel， and no purchase according to channel utility. Under the all-or-nothing mechanism， group-buying demand is realized as actual sales only when total group-buying demand reaches the threshold. The proposed model provides a framework for examining the interactions among pricing decisions， threshold setting， consumer role formation， and channel demand in social group-buying markets.
