We present an in-depth study of co-following on Twitter based on the observation that two Twitter users whose followers have simi- lar friends are also similar, even though they might not share any direct links or a single mutual follower. We show how this observa- tion contributes to (i) a better understanding of language-agnostic user classification on Twitter, (ii) eliciting opportunities for Com- putational Social Science, and (iii) improving online marketing by identifying cross-selling opportunities.
We start with a machine learning problem of predicting a user’s preference among two alternative choices of Twitter friends. We show that co-following information provides strong signals for di- verse classification tasks and that these signals persist even when the most discriminative features are removed.
Going beyond mere classification performance optimization, we present applications of our methodology to Computational Social Science. Here we confirm stereotypes such as that the country singer Kenny Chesney (@kennychesney) is more popular among @GOP followers, whereas Lady Gaga (@ladygaga) enjoys more support from @TheDemocrats followers.
In the domain of marketing we give evidence that celebrity en- dorsement is reflected in co-following and we demonstrate how our methodology can be used to reveal the audience similarities be- tween not so obvious entites such as Apple and Puma.