It's just what is says it is a social venue and a media source in that it usually provides one with valuable information. Just like TV and radio!
I wouldnt try to sell it to my boss...as she doesnt like me! lOL!!!
But I do use it to build my number of contacts. When I was training in sales I was told that every contact counts. And out of let's see 20 contacts....you should statistically make 2 sales....that's 20% success! Thus back to my previous statement....the more contacts you make...the better success you should have!
Social Media are places like twitter, facebook, ning, where people go to socialise online. A virtual meeting space.
Your company should use it to show their personal side. People are sick of nameless faceless companies who often treat customers like numbers. This is a way to build a positive relationship with customers, the community, and potential customers. It's a way for people to talk to your company without having to fill in a form - it can be a casual discussion rather than an official complaint/inquiry/suggestion.
You can measure it by using google analytics to see long term growth in web visits and where those people have linked from, how your product/service improves as you gain a better idea of what your customer wants thanks to their candid input, etc.
Everyone knows that word of mouth is the strongest form of promotion - 80% of people will look into something recommended by someone they know. And on social networking sites, people on average have 50 contacts each (a number growing each year). Of those contacts, 4 people are likely to forward something on to their own network (another 200 people), and so on. Social media is work of mouth multiplied in a way that person to person can't, and it has better response rates than advertising.
A good book to read is "The New Rules of PR and Marketing" by David Meerman. Get your boss to read it!