Thanks! I'm the author of the story. The NPR Visuals team works really hard to make stuff that is substantial but that people still want to read online. Obviously we're still learning and have a long way to go, but I share your hope and we'd love your feedback on how to make it better. A goal is to figure out how to do long form using some of these techniques.

For what it's worth the code that drives the story is open source: http://github.com/nprapps/lookatthis/