You remember Friendster, don’t you? That was the big social networking site a few years ago. Or how about Myspace? No?

Then maybe you’re repeating history and you don’t even realize it as you fill out your Facebook profile and think, “Wow, this is so cool!” Cory Doctorow has an excellent article entitled, How Your Creepy Ex-Co-Workers Will Kill Facebook, which explains why Facebook will be just another piece of social networking roadkill on the information superhighway in a few years.

The primary point he makes is that social networking sites are great when only your friends are on it. But once it becomes popular enough, it starts attracting everyone else who isn’t necessarily your friend… Your boss, the co-worker you hang out with but don’t really like, the guy you’ve been avoiding since college… And you inevitably face the challenge of having to add these unlikeable characters to your world because they ask you to.

Cory nails it with this quote, “In the real world, we don’t articulate our social networks.” And that’s very true, because to do so would mean to classify people into categories, some of which would be undesirable to the very people we categorize. We keep such things to ourself. That’s why it’s nearly always awkward when you have one set of friends meet another, like your “old school buddies” meeting your “newer, shinier co-workers.” The only commonality between the two groups is you!

Seinfeld probably first captured this awkwardness most of us avoid with the episode where George’s fiancee attempts to befriend one of George’s existing friends, Elaine — “It’s like two worlds colliding!” (See here for a short video clip as well as some blog commentary on this issue.) “Independent George” can’t exist in the same room with “Relationship George.” The same is the case with our profile on a social networking website. Once we have to open it up to others who aren’t in our closest circle of friends, we have to sanitize it and make it just a piece of who we are again.

Cory suggests this is the reason people are so willing to move from social network to social network. Facebook is attempting to stop the exodus by positioning itself as some sort of “platform” for real social applications, but this will only slow the people leaving (because for every Facebook application, there’s a dozen better applications that don’t rely on Facebook that already exist).

To put all of this into context, if you’re interested, I highly recommend reading Danah Boyd’s academic article, Social Network Sites: Definition, History, and Scholarship, which was published in October.