They may feature digital photo/video/sharing and "web logging" diary entries online (blogging).
Depending on the social media platform, members may be able to contact any other member.
In other cases, members can contact anyone they have a connection to, and subsequently anyone that contact has a connection to, and so on.
Linked In, a career-oriented social-networking service, generally requires that a member personally know another member in real life before they contact them online.
Some services require members to have a preexisting connection to contact other members.
For the social science theoretical concept of relationships between people, see Social network.
For a list of services, see List of social networking websites.
Orkut became the first popular social networking service in Brazil (although most of its very first users were from the United States) and quickly grew in popularity in India (Madhavan, 2007).
Through e-mail and instant messaging, online communities are created where a gift economy and reciprocal altruism are encouraged through cooperation.
Hence, the level of network sociability should determine by the actual performances of its users.