A local marketing agency had a huge wealth of postcode data from a mailing list that they needed to make sense of. Where were these places? Did they cluster in certain areas? Where should they focus their attentions.
Over the course of a few hours, I was able to clean up the data (remove duplicates, strip out the malformed postcodes etc), and then format it so that the online mapping service ZeeMaps could import it and see those patterns emerge.
The result – it turns out that half of city in question is ruled out, and most of the postcodes cluster around a few streets, so instead of printing and delivering leaflets to the whole city, only about a quarter were required saving cost, trees and wasted effort.