Measuring user influence on Twitter: A survey.

•We survey the several measures that exists in literature to rank influential users in Twitter network.•We propose a classification of these measures according to different criteria, such as the kind of metrics, the use of PageRank algorithm, the use of content analysis, among others.•Besides the influential users, we also study measures of activity and popularity.•We finish by mentioning some aspects of this topic related with computational complexity and correlation measures.