The answer to Marianina's question is, "Yes, I think Facebook is the most influential." But I don't know that because I use them all and have a strong opinion. I just read everyone else's opinions and see who I agree with.

I know I am supposed to be an expert on social media marketing—I speak about it a lot—but I have not personally spent a lot of time with social networks in particular.

I haven't yet joined Facebook (it's on my list) but I think it's the hottest place out there for businesses at the moment. I am in Linked In, but spend little time enhancing my standing—mostly just accepting the invitations of others. I, like many of us, am struggling with the idea of what kind of time is required to be in multiple social networks. I know it won't take long to set up a Facebook presence, but I am wary of how many different networks I "should" be in and how much time it sucks from my already busy days. Are there others like me that are concerned about the drip-drip-drip time drain of all this different stuff? Facebook is probably exactly the wrong example because it may be abundantly clear to most of you that I should be hanging out there if I do anything in social networking. But it occurs to me that I don't have a clear thought process around which ones deserve my time and which ones don't.

And I think I should. I'm really busy in the next few weeks upgrading my Web site to get ready for my new book coming out, but I feel like I should somehow go further than Linked In in terms of social networking. I wonder if there are others like me that maybe know that social networks are important but haven't yet taken the time to really exploit enough of them to be getting value from them.

So maybe I am not much of an expert here. I think it is easier to talk and write about stuff sometimes than to actually live it. My technology roots probably make me less comfortable with that than most people, so I am sure I will be dabbling in Facebook soon. But what about the next hot one that comes along? Each opportunity seems valuable in and of itself, but the crush of all of them adding up over time makes me wonder.