Valdis Krebs has posted an updated version of his political book map, based on Amazon buying habits. Political Patterns on the WWW -- Divided We Stand -- May 2004
The big difference between this network map and the previous two are the number of books in the middle. The release of two popular middle books, colored purple, expose a further network of middle books. Ghost Wars reveals one group of middle books, while The Rise of the Vulcans reveals a second group. Yet, the increase in boundary-spanning books does not indicate a shift in the political landscape. The three network maps are not that different within common statistical limits.
