Social Networking - When Is it too much?

The first time I became involved in social networking was with Friendster. Am I dating myself? That was abandoned with the rise of MySpace. Though I hadn't used Friendster in years, it was only this year that I deleted by my account once a friend alerted me to the fact that something to do with porn was being sent to my "friends". Initially there was some apprehension, should I alert those in my network? I didn't since most had also migrated to MySpace when I did. Then of course I moved to Facebook, the behemoth. Yet, I still retain the MySpace account.

This all leads to when does social networking become too cumbersome. Is there a possibly of having too many social networking profiles. And secondly does everything need a social networking component. I enjoyed imeem.com and last.fm, but I haven't filed out any additional information and definitely not "friended" anyone nor invited my friends to join. Perhaps I am just bitter because going.com sent out invites to basically everyone that I had every emailed or whose email addresses were part of a message to me. People I don't know or exchanged a message once are being asked to be my friend on going.com, a site that I see occasionally when I want to see what's happening on the weekend in NYC. It's annoying and that they can't retract the invites. It is beyond irritating.

Basically, what I am asking is why does everyone thinking that they need social networking in order to have a successful business? Just do your job. We all have MySpace, Facebook, Bebo, and Friendster. If we want our friends to know about something they will. Enough already! !

oh, I am signed up for LinkedUp. it's all too much already.