Apple vs. Android: a comparison of social effects in adoption Johannes Bjelland, Geoffrey Canright, Kenth Engø- Monsen, Pål Roe Sundsøy Telenor Research and Future Studies Telenor ASA, Oslo, Norway johannes.bjelland, geoffrey.canright, kenth.engo-monsen, pal-roe.sundsoy@telenor.com Rich S. Ling IT University / Telenor ASA Copenhagen, Denmark / Oslo, Norway rili@itu. I. INTRODUCTION It has long been known among marketers that our social network matters when we make purchasing decisions, and that having positive word of mouth about a product can be a key to success; see e.g. [1] for a review of studies on social networks within marketing. Traditionally, data on social networks have been difficult to collect, but in recent years researchers have gained access to massive social network data from e.g. online instant messaging services [8][5] and phone log data [2][4][3][6][9]. Such data has made it possible to study e.g. social churn [3], service uptake [2] among telecom customers, and product adoption on an Instant Messaging network [8].These studies confirm that consumer behavior is dependent on the communication network. We have in a recent study [6] shown how the structure of the adopter network—the social network of adopters—develops over time, and how social spreading can be measured by studying this network. In this paper, we do a comparative study of social spreading effects for two competing types of smartphones - the Apple iPhone, and smartphones based on Google’s Android OS. II. METHOD Our social network is built by collecting anonymized call data records, aggregated over a 3-month period, and then using the communication links (voice and sms) as proxy for the social relationships. Other studies have shown that mobile phone activity is a good way to measure real social relationships [3]. To remove error sources due to ‘non-personal’ relationships, we have applied some filtering of the dataset, regarding extreme outlier nodes (based on combinations of extreme usage and degree) as machines, and removing them. Only traffic between Telenor customers is used; calls to other operators are excluded. For this study we have also included weak links –relations with limited SMS/voice traffic in the period. In total we end up with a network containing around 2.5 million nodes and 45 million edges. We also use handset type data to associate a handset type with each node in the social network. With these data we can define the ‘adoption network’ – the social network among adopters [6]. This is simply the sub network consisting of adopters and their common links. We can then study the development of the adoption network for iPhones (viewed as a single ‘product’) [6]—and for Android phones, over time (again making no distinction among the various models of Android phones). These same data allow us to measure conditional adoption probabilities between neighbors on the network, which we use as an indicator of social effects. Finally, we use postcode information—very coarse-grained geographic information— on subscribers to map smartphone adoption to geographical areas in Norway. III. RESULTS In a previous paper [6], we looked at the growth of the iPhone adoption network over time, showing clearly the development of a ‘social monster’—a giant connected component of the adoption network which shows the fastest growth. We equated the strength of this monster with the presence of iPhone adopters in the ‘dense core’ of highly central subscribers—a sign of success of the product in taking off. In Figure 1, we compare the growth of the Apple adoption network with that of the Android adoption network, on a quarterly basis. In each case, we start with the quarter in which the ‘product’ was first launched. While we see no dramatic difference in the first–quarter picture (Fig 1(a)), it is clear that already, two quarters later (Fig 1(c)), the Apple ‘monster’ (Largest Connected Component - LCC) is growing much more rapidly than the Android monster. This holds not only for total number of adopters in the LCC, but also in terms of their percentage of all adopters: two quarters after launch, the Apple LCC has ca 38% of all adopters, while the Android LCC has around 28%.