<Li> Permanence: Industrial media, once created, cannot be altered (e.g., once a magazine article or paper book is printed and distributed, changes cannot be made to that same article in that print run) whereas social media posts can be altered almost instantaneously, when the user decides to edit their post or due to comments from other readers . </Li> <P> Community media constitute a hybrid of industrial and social media . Though community - owned, some community radio, TV, and newspapers are run by professionals and some by amateurs . They use both social and industrial media frameworks . Social media have also been recognized for the way they have changed how public relations professionals conduct their jobs . They have provided an open arena where people are free to exchange ideas on companies, brands, and products . Doc Searls and David Wagner state that the "...best of the people in PR are not PR types at all . They understand that there aren't censors, they're the company's best conversationalists ." Social media provides an environment where users and PR professionals can converse, and where PR professionals can promote their brand and improve their company's image by listening and responding to what the public is saying about their product . </P> <P> Social media have a strong influence on business activities and business performance . There are four channels by which social media resources are transformed into business performance capabilities: </P> <Ol> <Li> Social capital: represents the extent to which social media affects firms' and organizations' relationships with society and the degree to which the organizations' use of social media increases corporate social performance capabilities . </Li> <Li> Revealed preferences: represents the extent to which social media exposes customers' likings (e.g., "likes" and followers) and increases a firm's financial capabilities (e.g., stock price, revenue, profit), or for non-profits, increases their donations, volunteerism rate, etc . </Li> <Li> Social marketing: represents the extent to which social marketing resources (e.g., online conversations, sharing links, online presence, sending text messages) are used to increase a firm's financial capabilities (e.g., sales, acquisition of new customers) or a non-profit's voluntary sector goals . </Li> <Li> Social corporate networking: Social corporate networking refers to the informal ties and linkages of corporate / organizational staff with other people from their field or industry, clients, customers, and other members of the public, which were formed through social networks . Social corporate networking can increase operational performance capabilities in many ways, as it can enable sales staff to find new clients; marketing staff to learn about client / customer needs and demand; and management can learn about the public perceptions of their strategy or approach . </Li> </Ol>

When did the first social media site come out