Normally, the rationale for employing discounts as promoting strategy is the expected profitability improvement and lower cost for the vendors. Vendors expect an increased demand which can offset the impact of quantity discount offered (Viswanathan and Wang, 2003). Wang andWu(2000) argued that when there is an opportunity to achieve a lower price from a larger quantity discount, a buyer is more willing to propose a larger order quantity. Thus, in the setting of pre-determined discount-quantity schedules such as in Mobshop.com, customers are expected to form a bigger purchase group in order to get a lower final price. Based on this argument, the authors expected that the faster the price drops regarding groups size changing, the faster buyers will join in the purchase group, and thus, the faster the product will be sold out. By analyzing the performance of applying these three schedules in the experiment, it was hoped that this study can offer an intuitive insight of buyers’ responses to different price-network size schedules in a viral marketing setting and propose a suitable price schedule based on the results