Cory Doctorow nails it:
Content isn’t king. If I sent you to a desert island and gave you the choice of taking your friends or your movies, you’d choose your friends — if you chose the movies, we’d call you a sociopath. Conversation is king. Content is just something to talk about.
Or, if you could choose between your portable DVD player and a mobile phone…?
I think conversation is also the biggest difference between YouTube and GoogleVideo. Eventually Google had to buy YouTube to get into that conversation.