57% of teenagers create content for the internet—from text to pictures, music and video. In this new-media culture,people no longer passively “consume” media (and thus advertising, its main revenue source) but actively participate in them, which usually means creating content, in whatever form and on whatever scale.

This has profound implications for traditional business models in the media industry, which are based on aggregating large passive audiences and holding them captive during advertising interruptions. Instead of a few large capital-rich media giants competing with one another for these audiences, it will be small firms and individuals competing or, more often, collaborating. As with the media revolution of 1448, the wider implications for society will become visible gradually over a period of decades. With participatory media, the boundaries between audiences and creators become blurred and often invisible. This changes the tone of public discussions. The mainstream media, says David Weinberger, a blogger, author and fellow at Harvard University's Berkman Centre, “don't get how subversive it is to take institutions and turn them into conversations”. That is because institutions are closed, assume a hierarchy and have trouble admitting fallibility, he says, whereas conversations are open-ended, assume equality and eagerly concede fallibility.

The obvious benefit of this media revolution will be what Mr Saffo of the Institute for the Future calls a “Cambrian explosion” of creativity: a flowering of expressive diversity on the scale of the eponymous proliferation of biological species 530m years ago.

As editor of Wired magazine, Chris Anderson notes, “We are entering an age of cultural richness and abundant choice that we've never seen before in history. Peer production is the most powerful industrial force of our time." 

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