隨著網路科技的迅速發展，打破時間與空間的藩籬，電子商務系統逐漸被廣泛的使用，使得許多廠商可以透過網路的操作來販售產品與提供服務，而消費者也可以透過網路來購買產品與獲得產品資訊。而因應電子商務與網路購物行為的興起，不僅改變了原有的市場交易模式，也使得廠商得以實施許多創新的銷售策略，其中網路團購行為在近幾年逐漸受到廠商與消費者的關注，如Groupon團購網站的興起，Groupon為全球最大的團購網站，2008年於美國芝加哥成立，被《華爾街日報》（Wall Street Journal）和《富比世》雜誌（Forbes）同聲譽為有史以來成長最快的公司，並於2011年年底成功上市，使其成為Google公司上市以來IPO規模最大的一家科技公司。透過Groupon團購網站銷售的產品，每三件Groupon的促銷案中大約有兩件會獲利，僅有一件是虧損，意思是透過團購促銷的廠商有高達66%是可以獲利的。此外國內餐飲龍頭，如麥當勞與85度C，也紛紛加入團購市場，並獲得很好的成績。

本研究主要是以賽局理論模型探討在不同行銷環境下團購行為如何影響廠商之定價策略與市場的競合關係。其中發現消費者對產品的保留價格會影響廠商的團購策略與訂價策略，而廠商的團購策略也會進一步影響其訂價策略。透過模型分析，本研究並獲致以下結果：

 無論是在獨占或雙占市場，當廠商使用團購銷售產品後，因為會使游移顧客的數量增加，故會提升廠商訂低價來同時服務忠誠顧客與游移顧客的誘因，造成使用團購的廠商改變其訂價策略。

 無論是在獨占或雙占市場，當團購行為出現，市場上忠誠顧客對於產品的保留價格很高時，廠商不會使用團購，但當市場上忠誠顧客對產品的保留價格不高時，游移顧客相當重要，故廠商會使用團購。

 團購的出現會使低端消費者大增，改變原有的消費者結構，進而影響到廠商的訂價策略，並能有效減緩服務廠商之間的價格競爭。

With the rapid development of network technology, breaking the barriers of time and space, the e-commerce system has gradually been widely used, making many manufacturers can sell products and provide services through the operation of the network, and consumers can also buy products and obtain product information through the Internet. In response to the rise of e-commerce and online shopping behavior, not only changes the trading model of original market, but also allow manufacturers to implement a number of innovative sales strategies. The group-buying in recent years has gradually been concerned by manufacturers and consumers such as the rise of Groupon website, the world's largest Group-buying site established in Chicago in 2008. Groupon is also hailed as the fastest-growing company in history by the Wall Street Journal and Forbes magazine and was successfully listed at the end of 2011, making it the largest IPO company since Google listing for a technology company. About two of three products sale through Groupon sites are profitable, which means that the promotion are profitable for 66% and unprofitable for 32% of this company. In addition, the domestic food leader, such as McDonald's and 85。c, have also joined the group-buying market and get great results.

This research is based on game theoretic models to explore how group buying behavior in a different marketing environment will affect the pricing strategies of firms and co-opetition relationship in the market. We found that the reservation price of consumer for products will affect firms’ group buying and pricing strategies, and the firms group buying strategy will further influence their pricing strategies. Through the model analysis, we derive the following main results:

 Whether in the monopoly or duopoly market, it will enhance the incentives of firms to set a low price to service their loyal customers and switchers simultaneously when firms use the group-buying to increase the numbers of switchers.

 Whether in the monopoly or duopoly market, when the group-buying occurs, firms will not use group-buying strategy when the reservation price of loyal consumer is high. However, when the reservation price of loyal consumer is not high enough, switchers become very important so firms will use the group-buying strategy.

 The presence of the group-buying will increase the number of low-end consumers and will change the original structure of consumers, thereby affecting the pricing strategies of the firms, and can effectively reduce the price competition between the firms.

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5. 徐永昌(2012)，網路成癮對消費者團購意願之影響－以害羞為干擾變數探討之，中國文化大學國際貿易學系碩士論文。

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