And after AIM my friends migrated to Gchat. The real mystery to me is why Google let Gchat wither on the vine. For many years it was my primary way of chatting with friends. (Now it's iMessage.)
Google Talk appearing inside Gmail, and Facebook opening up to more than just .edu addresses both happened in 2006. Keep in mind, Gmail was still invite-only until 2007.
In 2008 Facebook introduced Facebook Chat, and ever since then Google has acted [1] to try to challenge Facebook for social networking -- and this caused Google's communication offerings to alternatingly be neglected or leveraged for that cause [2]. Google didn't win.
