Table 2 List of features derived from the Facebook advertising audience estimate data. All features, with the exception of Facebook penetration, are the fraction of Facebook users in the targeted location who use a given network/device type to access Facebook. All data are for users aged 18+. The Facebook penetration is the number of users divided by the total population of the location; where there were more estimated users than the estimated population the value was capped at 1. Note that according to the Facebook audience estimates, of all users who use a smartphone, the percentage who do not use either of the three specified Mobile OS types (Android, iOS, Windows) are 61% (India) and 51% (Philippines); of all users, the percentage who do not use either of the four specified network types (2G, 3G, 4G, WiFi) to access Facebook are 25% (India) and 37% (Philippines)

From: Mapping socioeconomic indicators using social media advertising data