The document discusses various types of social media and how they can be used for public relations purposes. It provides statistics on how social media has changed PR and notes that Facebook has over 799 million users between the US and EU. Twitter is described as facilitating quick communication and accessibility to brands. The document then gives tips on how to use Twitter for PR like developing relationships with reporters and bloggers. It also outlines different types of tweets and best practices for using LinkedIn and measuring social media effectiveness.