From my own review:
Cognitive Surplus starts with a potent historical parallel and an astonishing data point. Early 18th century England had a “Gin Craze” as the population tried to anesthetize themselves against dramatic social changes accompanying the industrial revolution. Shirky asserts television has played the same role over the last 50 years, absorbing the vast preponderance of free time in the developed world: “The sitcom has been our gin, an infinitely expandable response to the crisis of social transformation”. He takes a little time to catalog television’s pernicious effects, and makes the point along the way that the asymmetric dynamic between broadcasters and passive audiences of the 20th century media was an anomaly that isn’t going to be reinstated on the Internet any time soon.
The astonishing data point arises from a television producer’s reaction to his relating the story of Wikipedia: “Where do people find the time?” The impolitic answer of course is Wikipedia’s creators aren’t watching television. Shirky estimates that Wikipedia is the result of on the order of 100 million hours of work by a vast number of participants. This seems staggering until he puts it in context: Americans watch 200 billion hours of television every year and “we spend roughly a hundred million hours every weekend just watching commercials.” That tees up the book: there is a vast collective cognitive surplus available to be harnessed if we can just turn off the television. What happens when billions of couch potatoes begin to participate, create and share collectively?
With 173 million daily active users in the US and Canada, 50 minutes a day means 8.65 billion aggregate minutes a day or over 144 million hours, i.e. over a Wikipedia a day. And closing in on TV with over 50 billion hours a year. Never mind the rest of the world.
So “what happens when billions of couch potatoes begin to participate, create and share collectively?” Humanity’s noblest hopes are no match for cat memes and an echo chamber of clickbait.
And then there is the mystery of declining productivity growth. I’m sure it is just a coincidence that Facebook was founded right about at the 50 year peak in productivity growth and it has been all downhill ever since.