Taking a closer look at the ugly sister of social media.

LinkedIn is like the Ugly Sister of the social media world. Created before MySpace Bebo, Google Wave and Buzz, it’s not had the spotlight or the hype surrounding many other social media platforms.

But unlike the list above, LinkedIn has been online for almost ten years achieving steady growth and creating one of the largest social media sites on the internet.

In fact, the last few years have seen significant growth for the site on the back of new functionality developments and an improved integration with mobile devices, with mobile page views up by 400% year-on-year.

Many people don’t give this shrinking violet a second look. They create their own profile and only update it when they’ve had a bad day at the office. But it’s more than just a place to store contacts or look for a new job.

Here are five figures which might make you take a second look at the platform:

1. There are 131 million people on LinkedIn Worldwide, 5 million in the UK
2. There are over 150,000 companies listed and 870,612 groups
3. Half of all users are senior decision makers. The average income of users is over £50k
4. A third of users are 35-54 and 60% are men
5. LinkedIn revenues rocketed to $139.5 million (£88 million) this year

In 2008, LinkedIn followed on the heels of Facebook and created an applications platform that allows other online services to be embedded within a member’s profile page. This transformed the rather two-dimensional offering and expanded the offering from the site.

Companies can now position themselves more effectively as opinion leaders with SlideShare and Google Presentation allowing you to integrate your business talks, whilst WordPress applications can integrate your blogs onto your LinkedIn page.

Box.Net and Huddle Workspaces offer the ability to create collaborative documents. Tripit helps plan your work travel requirements whilst LinkedIn Events can create awareness for company activities.

But its not just about the off the peg poll applications and buzz monitors. Companies have been working with developers to create more ambitious APIs.

When Amex wanted to target more business consumers, they decided to turn to LinkedIn to do so. There aren’t many examples of successful case studies of multinational brands using LinkedIn for marketing so Amex were taking a risk. They developed an app for ‘Everything You Do’, which allowed people to nominate administrators in their companies for the chance to win a gift card courtesy of Amex, creating greater awareness of their products.

In Holland, Volkswagon focused on using the LinkedIn API to create a personalised experience, similar to Facebook Connect. The app compared LinkedIn profiles between contacts, encouraging you to complete your profile more. The campaign was competition-based, awarding a prize to the person that had the most complete LinkedIn profile. The beauty of this campaign is that it didn’t distract away from the main purpose of LinkedIn but actually encouraged people to use it more.

Ernst & Young were emotionally moved by a trip to Bangalore when they visited a local school. They used LinkedIn and Amazon to create a wish list of books and resources the school needed. They then contacted their connections to see if they could help buy the equipment desperately need.

Not all LinkedIn success stories are linked to applications. For example Irish Software start up company Goshido used LinkedIn to raise $230,000 (£145,000) in eight days. They sent out 700 messages to potential investors, and received over 200 responses after carefully selecting who might be interested in their proposition.

So isn’t it time you took another look at LinkedIn. Besides, beauty is more than skin deep.