I would love to hear what really caused this thing to collapse, although if you look at their traffic (attached) it seems rather steady. I always hear little snippets but never really understood what dismantled it. Obviously once the exodus to FB started to happen, it created a massive feedback loop.
Was it all the fake profiles? That it was more of a place to meet new people, rather than stay connected w old friends? I simply left because everyone went to Facebook. Personally, I always loved the full canvas and the personalization, better than FBs steril environment full of screwy UI/navigation.