Should I just drag all my friends into my social graph?

I may have to re-consider how I use the social networks I'm active on.

The benefits of the network effects can be summed up by that well-worn cliche: "the value of the network increases exponentially with the number of nodes in it."
The fact that "value" here applies to the entire network was pretty obvious to me, but a recent personal event reminded me that it applies to the individual nodes as well, and the value increases exponentially and gets particularly high as it reaches near completeness for the node.

Let me explain the reason for the gibberish above.

I got engaged recently, and wanted to let people know. I did it exactly the wrong way!
I happened to switch my status on Facebook (and a little later on Orkut) and was immediately inundated by messages, Wall posts and Scraps. I shot a couple of emails off to people that I knew though it was based more email address accessibility than thoroughness. I then just dealt with the numerous responses from the above. When I posted photographs from the engagement a month later, a bunch of other people suddenly discovered my engagement and got in touch.
The side-effect of this was I was at work, and not sure who knew I was engaged and who didn't.

I ended up not telling a bunch of people I wanted to, which mildly annoyed em and told a few people twice, which slightly amused them. There are still quite a few people, I really should have told by now, but haven't.

The point is, my social graph on Facebook/Orkut/LinkedIn is woefully incomplete, and I just realized how much is easier my life would be if more of my friends (and ideally anyone I wanted to contact) were on it. Which means suddenly there's a strong incentive for me to make sure more of my friends are on at least one of my networks, and ideally use it often enough so that they see my updates/messages etc.. My rules for adding friends/connections has always been to err on the side of caution, and not be a spammer. So I

• accept "friend invitations" only from people that I feel like I "know"
  
• don't invite anyone to a new network.
• even if they're already on the network, don't add them unless it seems like they're active on it.

But suddenly, I'm questioning that. If I can influence more people to come in to networks that I'm on, and become active users, doesn't my life become easier? Hmmm...