You may not have even heard of Second Life, but around 2006 are so everyone thought it was going to be the next big thing. You dressed up like an anime raver in a virtual environment so you could conduct business with virtual dollars. Yes, some people actually thought this was a professional environment that would be used for actual business transactions.
Good blogger explanation here.
"Second Life was originally developed in 2002-2003 on two reasonable but
ultimately wrong assumptions: That the desktop computer market would
continue growing, and that dedicated broadband lines would be the main
way people would access the Internet. Instead, the market largely
shifted to laptops, and now to tablets, and also to smartphones, all of
which depend on wireless Internet connectivity. The most popular
platforms for accessing the Internet now are the least conducive to
using Second Life, which performs poorly on wireless laptops, and can't
fully perform on smartphones or tablets at all. At the same time, social
networks, especially Facebook, provided many of the features that
Second Life offered, but in a way that was much less resource and
Why Second Life Failed from Slate
Article digresses into predictive model of which social media will succeed , but still interesting.