Well I don't know about all the silly knick-knacks but, as a communication tool:
1) It's less of an interruption than instant messaging: it's asynchronous communication rather than synchronous.
2) As asynchronous communication it's quicker and less laborious than sending email or text messaging. (Especially when contacting multiple recipients).
3) The newsfeed is probably the most efficient communication tool ever developed for telling multiple friends short snippets about what have you been doing / are planning to do.