Social Bootstrapping: How Pinterest and Last.fm Social Communities Benefit by Borrowing Links from Facebook

TL;DR

This paper investigates how copying social links from Facebook to new platforms like Pinterest and Last.fm helps build engaging communities, showing that such copying fosters connectivity, reciprocity, and interaction, especially among less active users.

Contribution

It provides an analytical model and empirical analysis demonstrating the effectiveness of social bootstrapping in creating connected, interactive online communities.

Findings

Copied links form a giant connected component with high reciprocity and clustering

Copied subgraphs exhibit higher social interactions than native links

Active and influential users tend to create native links with similar users

Abstract

How does one develop a new online community that is highly engaging to each user and promotes social interaction? A number of websites offer friend-finding features that help users bootstrap social networks on the website by copying links from an established network like Facebook or Twitter. This paper quantifies the extent to which such social bootstrapping is effective in enhancing a social experience of the website. First, we develop a stylised analytical model that suggests that copying tends to produce a giant connected component (i.e., a connected community) quickly and preserves properties such as reciprocity and clustering, up to a linear multiplicative factor. Second, we use data from two websites, Pinterest and Last.fm, to empirically compare the subgraph of links copied from Facebook to links created natively. We find that the copied subgraph has a giant component, higher reciprocity and clustering, and confirm that the copied connections see higher social interactions. However, the need for copying diminishes as users become more active and influential. Such users tend to create links natively on the website, to users who are more similar to them than their Facebook friends. Our findings give new insights into understanding how bootstrapping from established social networks can help engage new users by enhancing social interactivity.