From a speech he gave at the Web 2.0 conference in April 2008: Clay Shirky tracks the history of our cognitive surplus, explaining what we could, or needÂ to do with it:
So how big is that surplus? If you take Wikipedia as a kind of unit, all of Wikipedia, the whole projectâ€”every page, every edit, every line of code, in every language Wikipedia exists inâ€”that represents something like the cumulation of 98 million hours of human thought. [â€¦]
And television watching? Two hundred billion hours, in the U.S. alone, every year. Put another way, now that we have a unit, that’s 2,000 Wikipedia projects a year spent watching television. Or put still another way, in the U.S., we spend 98 million hours every weekend, just watching the ads. This is a pretty big surplus. People asking, “Where do they find the time?” when they’re looking at things like Wikipedia don’t understand how tiny that entire project is, as a carve-out of the cognitive surplus that’s finally being dragged into what Tim O’Reilly calls an architecture of participation.