What the essential of SNS?Is it important to you?

Nowadays there are many of SNS website that you can use or heared.for example,facebook,myspace,or twitter etc. But how we use it in our life? They say,they use them to make a friend or stay in touch with friends,but is it real? I'm not sure.In fact,as I know,many people spend a lot of time on them that is waste of time.
Yes,this is my opinion,I'd like write my life on blog instead of use SNS.you know people are often writing a short message on SNS.most of them are nonsence,chatter,or lip service.In the other side,as an audience,are you sure you really want to see that,are you sure it really helpful or useful for you.I doubt it. I think the real thing is these SNS satisfied people's curiosity.