Maps. The most basic of all data visualizations. Fun apps like CartoDB and Google Fusion Tables have made map building accessible to even the most primitive computer user. But how do you get a TON of data into a map? Well Google caps the size of the KML file you can layer into your map to keep congestion on their KML rendering service down (KML layers call back to google for rendering and then google delivers the rendered result back to your map). Third-party plugins for rendering KML on your own service can bog your server down if you haven’t properly cached results, have a ton of traffic or are feeding very large files to the service. But GeoJSON solves these issues by being light and client-side (beautiful, I know).