Facebook is on a huge roll right now approaching 500 million users worldwide. Most measurement services have them in the top 5 and some in the top 2 of most heavily trafficed websites in the world. They are in Google’s league in traffic and also starting to make traction with revenue. While they are not publicly traded yet, reports have them profitable and at a run rate of over 1 billion in revenue. They are for real and will be around for a while. In fact, Facebook looks to be the next Google where Google was the next Microsoft. I signed up for Facebook using my MIT alumni address back in 2005 when it was only available to students. I didn’t use it much but somewhere around 2008 it crossed the chasm into my generation and all of a sudden everyone I knew was on it. I still only used it periodically but more and more it is becoming part of my routine. I find myself learning interesting things there, including news and not just “so and so just ate a steak and feels full” but friends are linking to stories that I find interesting, sharing tidbits that spark interesting conversations and entertaining me with funny updates on their lives. It hasn’t yet taken over my iGoogle home page as the place I start my browsing experience but it is headed in that direction. I’m even conducting business on there, recruiting new hires, marketing new services and connecting with other entrepreneurs.

My question is, just as a site grows virally as Facebook has, is there such a thing as un-viral. What happens if the 5 hottest girls on a college campus decide they are bored with Facebook, that it is no longer cool and if you want to connect with them you need to reach them on some other site .com…well, boys will be boys and will head to that site and won’t that bring others off Facebook too. I’m not suggesting Facebook is vulnerable right now, quite the opposite but MySpace once looked invincible and while it is still around, making money and has lots of traffic, its not something I would bet on today. Could one group of cool kids, reverse the Facebook train or slow it down or have they reached such a critical mass and have such a powerful network effect that even the coolest of cool, the fonz himself can’t slow this one down.

I’m not anti-Facebook, I’m a fan. They are innovating quickly and bringing people together in new ways. I’m just saying, nothing lasts forever and what and when will change this?