Social Networking

The advantages of social networking to society are both career-related/corporate and social.
The business networking site Linkedin, which started in 2003, makes it much easier for employers to find employees, and vice versa. To quote Social Networking Technology Boosts Job Recruiting, by "Typing keywords into a search engine", an employer could "scrape the entire network to dig out high-quality candidates that she can't find elsewhere." Such sites also help job hunters market themselves online by setting up profiles, listing work history and specific skills.
Another advantage mentioned in the same article, is that "With social networking, I don't need to go to Bob directly to find out who Bob's friends are. Or Bob's friends' friends. So, effectively, I have a thousand contacts that could potentially lead me to 100,000, now I have 8,500 contacts that could potentially lead me to 4.5 million."
From a social  perspective, it is much easier to keep updated on friends' lives via social networking sites such as facebook if they live relatively far from each other or don't have much time or the means to socialize. On the downside, facebook privacy settings can be very unclear or confusing to the avarage user, resulting in embarrassing or unwanted consequences. An example of this situation was presented in the article Facebook Privacy Is So Confusing Even the Zuckerberg Family Photo Isn't Private, in which a photo posted by Mark Zukerberg's sister, Randi, was published on twitter in a way that she felt violated her privacy.
From the article: "Randi has indicated that she only wants her friends to see photos that she has posted. But the way Facebook works, friends of your friends tagged in a photo album also see the entire roll, unless you choose otherwise in the settings of the album posted. (It's not a universal setting.) The term "friends" in this album at right indicates my friends and all the friends of people tagged in the post. Changing that involves clicking "custom" and unchecking a box that reads "friends of those tagged.""
Another downside to having  a social networking site such as facebook in such widespread use is that spammers might take advantage of the data. these spammers might send you an email addressed to you by name, containing a link to a website that might result in downloading malware unto your computer. these scammers are exploiting the fact that  you're more likely to click on a link if it was sent by a friend.
From BBB: New Wave of Phishing Scams Uses Facebook Info for Personalized Spam:
"Scammers find your information through Facebook or other social media accounts. Some set up fake accounts and send out friend requests. When you accept the request, they can view your friends and personal and contact information. Other scammers rely on social media users not locking down their privacy settings, so basic information, such as your name, email address and friends' names, is publicly available."
 As I've read in the article Great Wall of Facebook: The Social Network's Plan to Dominate the Internet — and Keep Google Out, it seems Facebook's makers have a vision for the future of the internet as "Facebook - centered" rather than Google-centered, as it now is. To quote, "Facebook CEO Mark Zuckerberg envisions a more personalized, humanized Web, where our network of friends, colleagues, peers, and family is our primary source of information, just as it is offline. In Zuckerberg's vision, users will query this "social graph" to find a doctor, the best camera, or someone to hire—rather than tapping the cold mathematics of a Google search."
I personally think social networking have great potential in terms of advertising and key word search algorithm because of the amount of users in those networks, especially facebook. I don't think they could be a good replacement to vocal or visual interaction, but a very useful addition indeed.