I had the pleasure of being in the very first Facebook generation. My college was one of the first 13 to be added to Facebook, and we were all jazzed just to see photos of each other and occasionally get a "poke" -- the implications of which are not clear to this day.

I only have a couple of friends from college who are not on Facebook. The rest are. And I went to a college without a computer science department.

Generally the way new technologies spread, according to Geoffrey Moore's Cross the Chasm, are by starting with early adopters and spreading to the early majority. The early adopters are visionaries and do things simply for the sake of trying a new technology (e.g. being at the leading edge of "social networking"). The early majority are pragmatists who try something when they're sure of it's value (e.g. seeing what your friends are up to). Crossing from one to the other is a huge and often fatal challenge.

LinkedIn took this challenge and started with the early adopter Silicon Valley scene. They started to invite their friends, VCs, lawyers, bankers, etc. until it eventually spread so that many professionals -- even here on the East Coast -- know what it is. Reid said on my show that he doesn't think it's hit its "tipping point", but I believe it's crossed the chasm.

Facebook's another story.

Their first few thousand users included most of the college kids at the original 13 schools allowed in. While college students are more computer literate than many, most of that audience could not be considered early adopters. I had friends on Facebook in those days who didn't know what a blog was.

Facebook didn't start with the traditional early adopters, or if they did they only started with a small subset of them and didn't stay there long.

Moreover, they didn't even allow in the typical Silicon Valley/TechCrunch 53,651 early adopters in until recently (unless they happened to be in college).

Now, after Facebook has launched its API and the tech world has taken notice in a big way of the business opportunity in Facebook, you're starting to see lots of typical early adopters -- tech entrepreneurs and VCs (e.g. Fred, Josh, Roger, Dave, Howard, Andy) -- experiment with Facebook.

What does it mean that the early adopters are giving their two cents only after the early majority (at least among 18-30 year olds) have already adopted?