1. A geographic data visualization system, comprising: a computer device including: a mapping system for displaying a map having a plurality of geographic regions, wherein each geographic region is selectable and a selected geographic region is highlighted on the map; a demographic system for displaying demographic statistics for the selected geographic region; a matching system for automatically calculating and displaying a set of similar geographic regions once the selected geographic region is selected by automatically calculating a sum of absolute differences between data values in the selected geographic region with data values in other geographic regions for each of the demographic statistics, wherein the set of similar geographic regions is highlighted differently from the selected geographic region on the map, each similar geographic region highlighted with a shape having a size, wherein the size of each shape is related to a value of an absolute difference indicating a demographic similarity between a corresponding similar geographic region and the selected geographic region; and an adjustment system that allows a user to adjust the target value for the demographic statistics being displayed, wherein an adjustment to the target value causes the matching system to automatically recalculate and redisplay the set of similar geographic regions that have demographic statistics that most closely match the adjusted target value for the demographic statistics for the selected geographic region.