"Most user-generated content is created as communication in small groups, but since we're so unused to communications media and broadcast media being mixed together, we think that everyone is now broadcasting. This is a mistake. If we listened in on other people's phone calls, we'd know to expect small talk, inside jokes, and the like, but people's phone calls aren't out in the open. One of the driving forces behind much user-generated content is that conversation is no longer limited to social cul-de-sacs like the phone."
I've been trying to tell people this for years. Clay does a great job all through this book, by the way, of explaining how our online tools are changing group-forming, which is changing society. Another choice quote:
"I have a terrible singing voice, but my children would be offended if I played a well-sung version of 'Happy Birthday' on the stereo, as opposed to signing it myself, badly."