This document discusses altmetrics, which analyze the value of scholarly content beyond traditional citations. It summarizes Mendeley, a company that collects research data from users to provide altmetric measures of impact. Mendeley extracts data from the 2 million user profiles and 300 million documents uploaded to its platform. This data allows for faster and more comprehensive measurement of research impact than citation-based metrics alone. The document argues altmetrics are important to better understand what works in research and to serve all research stakeholders more quickly.