The Long Tail took form over nearly two years as an “open-source research project” on Chris Anderson’s blog at www.longtail.com. This experiment in book development, where he shared data and ideas in progress and many smart readers helped improve them, fleshed out the theory and stress-tested the analysis, which made the book far better than it would have been if he had worked on it in isolation. It also suggested applications in industries he never expected, from beer to fashion, which has hugely expanded the scope the research.