kids have already jumped ship. once their parents started 'fb-ing' they figured it was time to find something else.
they won't last in the spotlight forever. the whole social networking thing is like a swarm and swarms never stay in one place forever. another will pop up and the swarm will go there (or a few places).
the thing that annoys me the most is that webmasters seem to feel compelled to put up those stupid F and T icons and to join in that nonsense. if you are a company, you 'have' to be on both of those mindless services.
I'd like to see some icons that proudly state 'I'm NOT on fb or tw. I have no icons and nothing for you to follow me on'. I'd have more respect for the business if they put THAT on their website.