Who has time for #SMEM?

Over at LinkedIN, there's a PIO group:  #SMEM

http://www.linkedin.com/groups?gid=1932428&trk=myg_ugrp_ovr

and one on LinkedIN

http://www.linkedin.com/groupItem?view=&gid=1932428&type=member&item=76071533

One of the concerns I have about Social Media is, if we have PIO
groups on all, when will we have time to be Public Information
Officers?

http://en.wikipedia.org/wiki/List_of_social_networking_websites is the
list of social media sites, excluding the dating sites.

If we say we are going to join only the "popular" ones, who decides
"popular" and when they become "unpopular" for one reason or another,
what then?

http://en.wikipedia.org/wiki/List_of_defunct_social_networking_websites
is a list of defunct sites, including three Yahoo attempts but it does
not list the announced exit of Google Buzz.

I am on the big ones ... Facebook (hate it but I'm here), Google+,
Twitter, Pinterest, LinkedIN ... and still network on email groups both Yahoo and
Google. At some time, I am going to draw a line in the sand.

Have you drawn your line?

Where is it?