Social media allows for communication, entertainment, search, and business uses. There are many types of social media including blogs, microblogs, social networks, and hosting sites for video, photos, documents, and links. Jobs in social media include social media optimization, social media relations, and social media marketing. Social media works by allowing users to generate and share content that can then be found through both direct monitoring tools and indirect promotions and spam. Key performance indicators for social media include return on investment, various metrics, branding, public relations, advertising, and customer relationship management.