NEW YORK: PR Newswire (PRN) has launched Social Media Metrics, a social media monitoring, measurement, and analysis tool. Powered by Sentiment Metrics, the new tool monitors more than 20 million blogs, 5 million forum posts, 30,000 online news sources, social networks, and microblogs. The system can track keywords, target sites of importance, and isolate information such as geography and language. An Authority Score reveals the impact of a message or site and a Sentiment Report gauges positive, negative, and neutral messaging.