Who is using altmetrics tools?

« Over the past six years, since the publication of the Altmetrics manifesto, altmetrics have matured and greatly expanded. Applications are available to gather and display altmetrics data on articles and books alike, either from freestanding companies or from large publishing houses. But to what extent are researchers actually using altmetrics tools, and how does this relate to their use of more traditional citation-based metrics tools? (…) »