This is a fascinating demonstration of how search data can be taken advantage of to extract all sorts of information. Google Flu Trends uses search data to build up a picture of flu epidemics in the US. It makes me wonder what other sort of trends can be inferred from search data. Presumably lots of economic indicators could easily be extracted from search data in a similar manner - things like consumer confidence measures, measures of economic activity on a sector-by-sector basis, or other market indicators. The Google database is incredibly large, essentially cataloging the entire internet and people's search histories. There must be a lot that can be extracted from this vast amount of information.