Conclusions
Along with the surge of social networking platforms, social commerce, such as Groupon.com, has been growing rapidly by taking advantage of the influence of social networks in their business. This paper aims to contribute to an understanding of issues regarding social commerce, with a focus on analyzing the effect of social influence on deal sales from the perspective of social influence. Based on data on major social commerce service companies that offer a link or a widget button to well-regarded SNS such as Facebook and Twitter, we examine whether the amount of shared information through social networking significantly and positively increases sales. In doing so, we use the instrument-free method proposed in Park and Gupta (2012) to overcome the endogeneity problems in our estimation of the model. This method models correlation between the error term and endogenous variables via copulas and enables us to obtain consistent parameters for endogenous variables. Our empirical analyses using deal sales data yield an important result: consumer-generated social influence, such as from Facebook likes and Twitter tweets, boosts sales. Even after endogeneity is accounted for, the effect of Facebook likes and Twitter tweets is statistically significant with respect to deal sales. Therefore, our results confirm that customers’ voluntary sharing of deal information via social networks constitutes an important business model in social commerce or online commercial site in general. We also discuss that although consumer-generated social influence matters for sales performance, the channels of information sharing might also matter. We also provide some implications of our findings that can help increase sales on online commercial sites.