"Social media marketing is an umbrella term that includes the use of social media for sales, marketing, customer service and public relations, indicating a convergence of these traditionally separate corporate departments. Social media consists of online technologies, practices or communities that people use to generate content and share opinions, insights, experiences and perspectives with each other (Television Bureau of Advertising, Inc., 2009). Examples include blogs (e.g. Blogger, Wordpress), intranets, podcasts, video sharing (e.g. YouTube), photo sharing (e.g. Flickr), social networks (e.g. Facebook, MySpace), wikis (e.g. Wikipedia), gaming sites, virtual worlds (e.g. SecondLife), micro-blogging (e.g. Twitter), videoconferencing, instant message chats, social event/calendar systems (e.g. Eventful), social bookmarking sites (e.g. Delicious, Digg, StumbleUpon), and news aggregation sites, among others. In the last decade these technologies have risen in popularity and ubiquity, and are being utilized by public relations practitioners to perpetuate the ever-changing industry of corporate communications."

Laura Matthews, Social Media and the Evolution of Corporate Communications