Ouch! I wouldn't try to do it on 75,000+ reblogs. Since Tumblr doesn't expose reblog data via their API, I have to manually go and load 50 notes at a time via t

Ouch! I wouldn't try to do it on 75,000+ reblogs. Since Tumblr doesn't expose reblog data via their API, I have to manually go and load 50 notes at a time via the urls from the 'more notes' link. Each request takes about 700ms and is ~75kb of markup. For 75,000 reblogs that would take about three hours. Plus, rendering them all - keep in mind this is O(V^3). Definitely not optimized. That's why I suggest a typical maximum of around 500 notes to visualize... Adding metadata for each node on-hover is definitely, definitely on my to-do list. That will make it useful and not just a toy, I think. Some other metadata besides just which tumblr each node represents that I want to get on there eventually is its centrality.