By comparing the amount of light in each unit of the grid with reliable sources of economic data from advanced economies, Chen and Nordhous established a clear and compelling relationship between radiance levels at night and GDP.

FORBES: The Case for Keeping the Lights On

The media-modeling tool was kicked into high gear two years ago when Chad Jacoby, senior manager of Nissan's Business Intelligence Unit, used years of Nissan's consumer research to build a computer model comparing the relationship of each phase of their "purchase funnel"--from awareness to purchase consideration to a transaction--to the phase before it.

FORBES: Ad Vantage