Facebook vs. Google+ vs. Twitter vs. LinkedIn

Network World - Much has changed since we examined the ongoing war between Facebook and Twitter in the spring of 2010. The stakes are higher, the competition has increased, and we see LinkedIn and Google roaring into the social networking arena like never before.

A year and a half ago, you might have thought the reverse would have happened - that Facebook and/or Twitter would have crushed any remaining competitors and that would be the end of it.

Instead, what happened was that LinkedIn and Google were able to find unfilled niches, and we now have four different major social networks, each with its own specialty, but with major overlaps.

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The biggest point of overlap is in sharing news and other content online. Each site provides a mechanism for sharing the latest headlines with your friends and colleagues. Caught in the crossfire are sites that specialize in social media, where users submit and vote on Web content - and so we have seen weaker social media sites like Digg and Delicious struggle, while stronger sites like StumbleUpon and Reddit have hung in there.

Of the big four, Facebook is still the big kahuna. It now has more than 800 million members. In April 2010, analytics site Compete.com said Facebook attracted 135.4 million unique visitors, and that number improved to 156.3 million in September 2011.

What sets Facebook apart is its personal nature - and this has been both a blessing and a curse. People turn to Facebook because it is the place where more of their friends are sharing photos and general updates on their lives. The flipside is that, because people see Facebook as so personal, they are shocked when Facebook tries to leverage their personal information, and they get upset when the interface changes with new features.

Twitter benefits from its immediacy and its simplicity. At 34.7 million unique visitors in September, according to Compete, it still has a fraction of Facebook's visitors, but has seen 60% growth since spring 2010, vs. Facebook's 15%.

Twitter doesn't suffer from Facebook's personal-information problem. Apart from the occasional congressman, most people regard Twitter as a more public place, a place to share news, chime in on public events and see what others are saying about them, and this formula has remained constant. If you want the world (as opposed to just your friends) to know about something, you go to Twitter, not Facebook.

LinkedIn was always around, but in recent months it has stepped up its efforts to be more relevant to its users. These efforts appear to be successful, with monthly unique visitors rising more than 80% to 23.8 million, according to Compete.