Altmetric is a small London-based start-up focused on making article level metrics easy. We've created and maintain a cluster of servers that watch social media sites, newspapers and magazines for any mentions of scholarly articles.

In mid January 2012 we were tracking approximately three thousand unique papers a day. We have broad coverage and are getting better every month - we can track articles from hundreds of different publishers, preprint databases and institutional repositories. If somebody has recently tweeted, blogged or posted a public link to your paper then we quite possibly know about it.

We clean up the data, disambiguate articles and give each one an Altmetric score.