At launch, Twitter’s story wasn’t very compelling. The site let you post what you were doing in 140 characters or less. Definitely not disruptive.

But 10 months later or so Richard is naming them best little web co of ‘07. He even specifically calls them out as one of the few disruptive technologies of the year.

So what changed? Well, the idea caught on, it evolved, and it scaled.

We get so many inquiries from entrepreneurs looking to launch disruptive ideas that I get excited any time a prospect says they aren’t sure what to expect at launch, or, better yet, that they aren’t even worried about the initial reception.

Disruption almost never occurs at launch, and forecasting it is impossible. (Odds improve w/ Steve Jobs on staff.)

But don’t let that stop you. Consider launching light. Think beyond launch. Let your idea evolve. Help it scale. Work toward disruption.

I had a conversation a while back with someone who wanted [us] to build [them] “Twitter with a purpose”. They knew it was popular, could wrap their mind around the technical spec, but really gave no credit to the app’s value.

If you see Twitter as a mechanism to post and display brief messages, set up light profiles with followed / follower relationships, and offer a straightforward API, then, yeah, we can probably build it for you. But giving that app purpose to even a fraction of Twitter’s participants would be something else entirely. Even if your purpose is all the money.

To be fair, it’s pretty easy to miss Twitter’s good parts. If you throw a tweet over the wall now and then and have sms notifications turned on for twits like me, it’s going to seem like one big cluster. But get inside it for a while, and you begin to see what makes it grow. It’s not a single purpose. It’s the open platform that spawns all kinds of purpose.

There’s absolutely no way the dev crew planned for it to go this way. So, if you’re looking to emulate, you’re going to need a lot more than a similar spec.

If you’re still not buying that Twitter shows any redeeming quality, switch the example to craigslist. Again, we could certainly deploy an app with similar functionality and even improve the user interface, but that alone would never capture a similar following.

Need another example? How about MySpace? Virb makes MySpace look like it was built by a monkey armed with Paint and a trial version of HotMetal Pro. But where do the people go? To the cluster.

Another? Digg. Pligg won’t be knocking them over any time soon.

So what makes one site lock on so effectively, and the next die? Your guess is as good as mine.

But if you look at the entire [Web 2.0] category, I think you’d see that the popular apps are those that follow / respond to their community vs those that try to lead it. Maybe some ambiguity of purpose is good.

One thing’s for sure, that guy’s never going to pay us to build him his Twitter clone.