Online communication in the form of messages and information exchange on social networks has become a significant part of human communication. Social networks are facilitating inter-personal communication and the dissemination of all kinds of information and media content. As online messages and information exchange on social networks increase, more social networking sites have emerged around the world. Some of the notable ones are Nexopia (Canada), StudiVZ (Germany), iWiW (Hungary), Tuenti (Spain), Orkut, and Hi5 in South America and Central America. Other social network sites are Friendster, Gowalla, and Bebo. A good list of social networks is available on Wikipedia.org at: http://en.wikipedia.org/wiki/List_of_social_networking_websites.
There are social networking sites for almost every human activity. However, there are two broad categories of such networks: profit and non-profit social networks. Examples of profit sites are:
Gurgle—a social...