Emily Underwood on new cartographers and the growing field:
Geographers have traditionally studied how the natural environment contributes to human society and vice versa, whereas cartographers have focused more explicitly on the art and science of mapmaking. Over the past couple of decades, a new field has emerged: geographical information systems (GIS), blending the study and expression of geographic information. Cartography and geography have overlapped and spawned innumerable subspecialties and applications. Modern geographers and cartographers are involved in diverse projects: tracking fleets of vehicles or products, helping customers locate a Dunkin' Donuts, modeling environmental scenarios such as oil spills, and studying the spread of disease.
You could substitute visualization and statistics for cartography throughout, and it'd almost all still be valid. The reoccurring theme is that although academic programs can be fine resources, most of your success has to do with what you can learn on your own, as data-related fields are changing fast.