Altmetrics are alternative metrics used to measure the impact of research. Altmetrics have the potential to "provide a broader, more diverse view of the impact of any piece of scholarship, to reflect the impact of the article itself, not its publication venue, to track impact outside the academy, to track the impact of influential but uncited work, and to track impact from sources that aren't peer-reviewed." (source: http://altmetrics.org/manifesto)
Altmetrics track research impact by quantifying: