Social Media is media designed to be disseminated through social interaction,

Social media can be said to have three components;

1. Concept (art, information, or meme).
2. Media (physical, electronic, or verbal).
3. Social interface (intimate direct, community engagement, social viral, electronic broadcast or syndication, or other physical media such as print).

The need for a social media in companies and organisations cannot be over emphasised because major decisions are based on analysis of information and feed back mangement can lay their hands on.

A working example of a social media is:

Yammer is a web based social media targeted at making companies and organisations more productive through the exchange of short frequent answers used to one simple question: "what are you working on?"

It's presently being used by Employees at More Than 50,000 Businesses Worldwide. As employees answer that question, feed is created in one central location enabling co-workers to discuss ideas, post, news, ask questions, and share links and other information. This platform also serves as a company directory in which every employee hass a profile and as a knowlegde base where past conversation can be easily accessed and referenced.

Anyone in a company can start their Yammer network and begin inviting colleagues as privacy of each network is ensured by limiting access to those with a valid company email address.

The basic Yammer service is free though Companies can pay to claim and administer their network.

The idea of Yammer is driven by the need of companies to share information witin a private network i.e. Information is never shared with third parties

if you want to check out Yammer go Here and start collaborating