Recently, a new e-commerce business model is booming. It is an electronic-coupon based group-buying model. Its prosperous development has formed a big online group-buying market in which many new websites run similar electronic-coupon based group-buying models. This new electronic-coupon based group-buying model is very different from the traditional one. It is not only that the main type of the products is service-oriented, but also that the object of transaction is electronic coupons which provide the consumers privileges of getting the services in a limited time period. It completely changes consumer behaviors. For these reasons, this study explores how the electronic-coupon based group-buying model succeeds by reviewing the literature and analyzing the data collected from the online website. The results show that both the promotion price and discount rate impact the group-buying performance but the discount rate will have more impact than the promotion price. Further, the limited sale is a good strategy to improve the group-buying performance. Overall, the electronic-coupon based group-buying model performs well in restaurants, cinemas and entertainment industries.