The early diffusion of mobile social networking (MSN) reflected the interplay of different factors: the affordability of better Internet connectivity and the diffusion of Smartphones suitable for Social Networking Applications. These key technology and cost drivers facilitated both the direct and indirect network externalities, which are necessary to overtake critical adoption barriers and facilitate users' decisions. However, a key challenge in modeling MSN diffusion is in distinguishing among the impact of these two types of network externalities. This paper addresses such a challenge by adopting a two-stage estimation strategy. In the first stage, we focus on direct network externalities by estimating a set of country-specific adoptions peaks that allow differentiating between early and late adopters. In the second stage, we estimate the impact of indirect network externalities on MSN diffusion while also considering the role of pricing strategies. Our results provide significant evidence that indirect network externalities can exert opposite effects on adoption between early adopters and followers, depending on whether they adopt before or after a country's MSN diffusion peak.

移动社交网络 (MSN) 的早期传播反映了不同因素的相互作用：更好的互联网连接的可负担性和适用于社交网络应用程序的智能手机的普及。这些关键技术和成本驱动因素促进了直接和间接的网络外部性，这是克服关键采用障碍和促进用户决策所必需的。然而，建模 MSN 扩散的一个关键挑战是区分这两种类型的网络外部性的影响。本文通过采用两阶段估计策略来解决这一挑战。在第一阶段，我们通过估计一组特定于国家/地区的采用峰值来关注直接网络外部性，这些峰值允许区分早期采用者和晚期采用者。在第二阶段，我们估计了间接网络外部性对 MSN 扩散的影响，同时还考虑了定价策略的作用。我们的结果提供了重要的证据，表明间接网络外部性会对早期采用者和追随者之间的采用产生相反的影响，具体取决于他们是在一个国家的 MSN 扩散高峰之前还是之后采用。