Digital Science has released Altmetric Mentions and the Communication of Medical Research.
Here's an excerpt:
Social and mainstream media mentions of research publications appear much more rapidly than conventional academic citations and are generated by a wider range of users. They therefore offer the potential for early and complementary indicators of research impact. Such indicators could also identify new kinds of economic and social impact.
In this report we explore the relevance of such new indicators to research in medical and health sciences.