Altmetrics is the creation and study of new metrics based on the Social Web for analyzing, and informing scholarship. It goes beyond traditional citation-based indicators and raw usage factors such as downloads or click-through numbers. Instead it explores readership, diffusion and reuse indicators that can be tracked via blogs, social media, peer production systems, collaborative annotation tools, including social bookmarking and reference management services. Read more about Altmetrics in Altmetrics manifesto.
Noteworthy altmetrics tools and services.
Mendeley is an online research-collaboration platform and academic database. Mendeley's metrics include how often papers are downloaded, shared with colleagues, and commented on. You can download this software for free.