Structural diversity and tie strength in the purchase of a social networking app
研究发现，社交网络用户更可能为拥有结构多样且规模大的社交网络付费，且个人关系（家人朋友）比职业关系更能促进购买。
Although people increasingly rely on online services to maintain their relationships, we know relatively little about what drives their use. To address this, I analyze data from a social networking site that started charging its users for an app that populates their e‐mail address books with updated contact information. I find that purchase rates of the app were higher for users with large, structurally diverse networks – which contain several distinct social groups. Moreover, personal ties (i.e., family members and friends) increased purchase rates more than professional ties. I attribute the first effect to the difficulty of obtaining information about a large, diverse social network, which the app reduces, and the second effect to the regularity with which people use information about their personal ties.