Do you Facebook?

Launched on February 4, 2004, Facebook was founded by Mark Zuckerberg, a former member of the Harvard class of 2006. Initially the membership was restricted to students of Harvard College. It was subsequently expanded to all Ivy League schools within two months. Many individual universities were added in rapid succession over the next year. Eventually, people with a university email address from institutions across the globe were eligible to join. Networks were then initiated for high schools and some large companies.
Since September 11, 2006, it has been made available to users with any email address if they are within a certain age range. Users can select to join one or more participating networks, such as a high school, place of employment, or geographic region.

What was first an intra-university website has now become one of the most powerful social network on the internet with more than 50 millions users all over the world. Its success can be explained by the numerous applications you can find on it: photo and video sharing, personal profile - including matrimonial status, religious and political views, nationality etc, a "wall" where everyone can post a note and many more funny apps such as personality tests, movie rewiews...
Of course advertizers have been interested by such a source of personal informations, freely shared and shown by the many users...
That's why Mark Zuckerberg, Facebook's 23 year old chief executive announced on november 6th that Microsoft had purchased a 1.6% stake in Facebook for $240 million - when Google had failed in his attempt.
In a word, Microsoft's strategy is to buy a part of Facebook - when buying the entire company is way too expensive, its value being estimated of $15 billion - in order to be Facebook's exclusive partner in publicity and thus to position on a juicy market.