How new is big data? First point is that the library of Alexandria was a good first attempt at collecting over 900k manuscripts. At its moment in time, that represents big data.
Today, there are about 6.8bn mobiles in the world. Roughly the same as the number of people in the world. We also spend more time with our phones than with our loved ones. It represents a gold mine of data, if it can be anonymised and aggregated.
An example: Mimos ice cream shops in Bogota. By adding a climate layer to maps along with map of mobile phone usage in an area to find the best time to launch an ad.
But there's also room for big data for social good.