I totally agree, that's the point of my comment even. This is a moving target, nothing 'always' about it. We're discussing the decline of facebook over time, an

I totally agree, that's the point of my comment even. This is a moving target, nothing 'always' about it. We're discussing the decline of facebook over time, and it started being popular with an entirely different age group than it is now. I also think it's worth noting these are relatively new phenomenon, we haven't even had social networks for long enough to pin down trends so absolutely.