The Psychology of FB Updates

And why exactly is FB such a big hit? What is the magic behind that irresistible urge for updating statuses?

Been thinking about it, and the only thing that comes to mind is - the Need for Attention, for Social Validation.

Uploading new photos, writing witty status messages, or commenting - everything finally leads to the child in our heart that desires attention.  FB is such a fantastic tool to study psychology, really!  Researchers, anyone??