Peer influence in a very large social network: the diffusion of the iPhone handset

In this paper we analyze a large-scale comprehensive dataset from a major European Mobile Phone Provider (EURMO). This dataset allows us to study the diffusion of the iPhone 3G. We provide evidence of contagious adoption. We show that the propensity for iPhone 3G adoption increases with the number of individuals within the social network that have previously purchase the iPhone. We bound the impact of social influence to 14% of all iPhone 3G adoptions observed in EURMO. This result is obtained after controlling for social clustering, gender, previous adoption of mobile internet data plans and ownership of technologically advanced handsets as well as heterogeneity in the regions where subscribers move during the day and spend most of their evenings. This result shows that the effect of peer influence is not trivial and that targeted marketing campaigns to spread handset adoption over mobile networks might indeed be worth pursuing.