Just thought it would be interesting to list a few of the social media sites that have been bought over the last few years.
Facebook buys Instagram
Facebook buys Gowalla
Facebook buys friendfeed
Linkedin buys Slideshare
With so much spent on the successes it is easy to forget all the once great sites that fail for one reason or another. Bebo has lost masses of users, there is a good summary by the Guardian here