Great example. How long have you been running it? How did you get on the front page of Reddit?
I already had some success on Reddit, where I created interesting map charts with it (like religiosity by US state, most popular browser by country,etc.) and shared the link to the site in the comment. This got me many users that would either come directly from the Reddit post or see another map somewhere and google my site.
The big spike came last May, when I shared it on /r/InternetIsBeautiful (https://www.reddit.com/r/InternetIsBeautiful/comments/4jcadt...) , which is a specific subreddit for internet tools and single-purpose website, and it propelled to the front page.