Shared publicly  - 
I have understood why Google Wave failed, and why Google Plus is in danger:

Lack of pervasive visualization tools for handling steadily increasing amounts of data over time in a users' realm (i.e. a stream, a wave, a shared Google Document, etc.)

Think video tapes: Would you have used them (if you are old enough to actually have done so) if you had had only normal playback speed, backwards and forwards, to search an 180 or 240 minute tape?

Now consider DVDs, then the DirStat utility or the lavaps utility.

Now, think. Then discuss.
Add a comment...