Former Linden Lab Evangelist, Rueben Steiger has run the numbers and determined that with Second Life's current growth the grid will be bursting with 3.6 million residents by July 1, 2007. Given the current rate of 22% monthly it may seem unlikely that such a high rate will be sustainable over the long term. However, he further postulates that if the growth rate diminishes to a measly 10%, there will still be nearly 1 million residents in the same time period.
This brings up the question; will Second Life be able to handle the load increase 3.6 million residents would add? Either way, the predicted grows is staggering and tells me things are just starting to get really interesting.
