You can look at Facebook as having launched independently in a number of different markets.
Initially it was Harvard (2003), then Ivys (March, 2004), then selective colleges, then all edus. It then tapped high-school students (September, 2005). It was opened to the general public in September 2006. Introduction to other countries also generally came later in the game, and FaceBook have had to compete with alternative networks, particularly in China and Russia. (Most data here from Wikipedia's Facebook article).
It's helpful to look at each of these as a somewhat independent social network.
We're hearing now about significant defections (or failures to join) in the < 25 market. Facebook's growth overall in the US peaked ~2010-2011. It's been growing outside the US, but that's a much less lucrative market for advertisers. Breaking out growth / user patterns by introduction point would be particularly interesting as I suspect this would model earlier social network growth more accurately.
Initially it was Harvard (2003), then Ivys (March, 2004), then selective colleges, then all edus. It then tapped high-school students (September, 2005). It was opened to the general public in September 2006. Introduction to other countries also generally came later in the game, and FaceBook have had to compete with alternative networks, particularly in China and Russia. (Most data here from Wikipedia's Facebook article).
It's helpful to look at each of these as a somewhat independent social network.
We're hearing now about significant defections (or failures to join) in the < 25 market. Facebook's growth overall in the US peaked ~2010-2011. It's been growing outside the US, but that's a much less lucrative market for advertisers. Breaking out growth / user patterns by introduction point would be particularly interesting as I suspect this would model earlier social network growth more accurately.