中文摘要：

基于团购网站和销售商的典型合作模式，考虑了团购网站和线下市场的相互影响，用非线性优化理论为基础以销售商制定团购上限和团购项目定价为决策变量，考虑团购价格和最低团购数量的约束条件，建立模型优化：求解出销售商推出团购项目的最优策略。考虑到团购网站下限和团购网站销售成本以及网上销售的广告效用，分析了销售商是否应该制定团购上限，如何结合团购项目定价制定团购上限。探讨了在线低价限量销售的优势，以及顾客转移购买率和团购下限对销售商策略选择的影响。通过和单一线下渠道的最优销售策略相比较，得出销售商推出团购项目的前提条件。同时为团购网站运营商如何引导销售商推出低价团购项目提供了管理启示。

英文摘要：

Group-buying（GB） website is a very popular online platform for sellers offering products/service with discount in recent years. This paper builds an analytical model for sellers selling on GB website to make optimal decisions on pricing and setting deal size based on a typical GB deal structure. With a view of the cost, the re- quirement of minimum deal size and the interactions between GB website and offline market, it provides manage- rial insights for the seller on whether to set a cap on the deal size and how to set the maximum deal size with com- bination of pricing. We first derive three optional strategies for sellers under varying exogenous conditions. We show that it may be optimal for the seller to set a maximum deal size limit even though there is no capacity limit. This upper bound of the deal size can be a strategic tool to shift customers from online to offline even if there is a customer loss. With the upper bound on deal size, we show that selling at a discounted price below cost or even for free can be an optimal strategy for sellers if the minimum deal size set by the GB site is not high. We also in- vestigate how the customers＇ transfer rate and the minimum deal size set by the GB website affect seller＇ s opti- mal selection on the GB deal. Comparing with the optimal strategy of selling through single offline channel, we derive conditions under which selling through GB website is better. It shows that selling through GB website is beneficial to sellers when there are enough new customers on the GB website and the overlap of customers be- tween GB website and offline channel is not large. This paper also provides suggestions for GB website on how to induce seller to offer deep discount on the GB deal including adjusting the GB sale fee and the minimum deal size.