Relationships between article-level metrics.

For articles published between 2006 and 2009, there is a positive correlation between the number of times an article is cited in the scientific literature and the number of times it is viewed (A). For articles published between 2010 and 2012, there is a positive relationship between the number of views and the number of citations in the Mendeley social network (B). Metrics, such as number of views and citations in social media, give readers and authors an estimate of the scientific impact of individual articles well before they receive citations in scientific literature.