社群網站競爭模型

Abstract

近年來社群網站越來越流行，使用人數增加，人們花在上面的時間也越來越多。由於市場極具潛力，因此越來越多企業加入這個市場，市場競爭日趨激烈。然而，目前所提出的許多競爭模型，皆未考慮到社群網站的特性。因此，在本篇論文中，我們首先找出影響社群網站競爭力的因素，接著利用這些因素建構兩個競爭模型:同質及異質。在同質競爭模型中，使用者的內在喜好是一致的(沒有差異性)；而在異質競爭模型中它則有明顯的差異。然後，我們分析兩個競爭模型的投資策略，並根據使用者本質比較其兩個模型的差異性。分析結果顯示由於網路效應，一個網站的投資金額隨著使用者人數的增加而減少，但隨著競爭網站的使用者人數的增加而增加。當競爭網站的邊際利潤增加，使用者為同質時，投資金額會上升；若使用者為異質且競爭網站的邊際利潤大於網站本身的邊際利潤時，投資金額則會下降。當網站的邊際利潤增加，使用者為同質時，投資金額並不受影響；使用者是異質時，投資金額會減少。而網站的利潤隨著邊際利潤與使用者人數的增加而增加。在同質模型中，由於網站的投資金額，隨著競爭網站邊際利潤與使用者人數的增加而增加，因此，其利潤將減少；在異質模型中，由於網站的市場大小，隨著競爭網站邊際利潤與使用者人數的增加而增加，因此，其利潤將增加；所以，隨著競爭網站邊際利潤與使用者人數的增加，使用者是異質時，網站的利潤將增加，但使用者是同質時，網站的利潤將減少。由於邊際利潤與使用者人數對於同質與異質模型有不同的效應，因此，我們建議對不同本質的使用者，應有不同的最佳化策略。

Social Network Sites (SNSs) have grown rapidly and become more and more popular in recent years. As SNSs have a great potential to earn profit, many companies try to operate their own social network sites to earn benefits. As a result, there are a lot of competitors in the market. Although many competition models have been developed, they do not consider the specific features of SNSs. Therefore, in this thesis, we first identify the features of SNSs and then utilize these features to propose two competition models of SNSs, namely, homogeneous and heterogeneous. The users are homogeneous in terms of intrinsic preference in the former model while they are heterogeneous in the latter model. Then, we analyze and compare both models according to users’ constituents. The analytical results show that the investment of one site A decreases with the number of users in site A; however, it increases with the number of users in the rival site B if the number of users in site A is not much smaller than the number of users in site B because of network effect in both models. In addition, as B’s marginal profit increases, A’s investment increases in the homogeneous model and increases in the heterogeneous model only when B’s marginal profit is larger than A’s. Also, as A’s marginal profit increases, A’s investment decreases in the heterogeneous model; however, it is irrelevant in the homogeneous model. As for the profit, the profit of site A increases with A’s marginal profit and the number of users in A in both models. As B’s marginal profit and the number of users in B increase, A’s profit increases in the heterogeneous model; however, it decreases in the homogeneous model. This is because A’s investment increases with B’s marginal profit and the number of users in B in the homogeneous model, and thus A’s profit decreases. Nevertheless, A’s market share increases with B’s marginal profit and the number of users in B in the heterogeneous model, and thus A’s profit increases. Since the effects of the marginal profit and the number of users on the sites’ investment strategies and profits in the homogeneous model are different from those in the heterogeneous model, we suggest various optimal strategies for different user constituents.