Hundreds of thousands of emails are sent every second, and yet, you wouldn't really know it because there aren't public-facing streams like that of Twitter. Outside your own inbox, how much email is there exactly? Yahoo, in collaboration with information visualization firm Periscopic, shows you how much email they process in real-time with this interactive feature.
The initial view is a world map, and scaled bubbles represent how many emails were currently sent. Hover over continents for user geographic distribution and gigabytes sent.
There's also trending topics from anonymized subject headers via streamgraph. The view is interesting as you can click on sections so that the surrounding streams split, so you get a sense of distribution along with details per keyword. The keyword data, however, isn't all that interesting for the most part. You'll see keywords such as online, free, and nights. Not too meaningful. There are a few exceptions though like Oprah and wars.
There is also an option to include spam keywords with equally generic terms.
Finally, if you go back to the map and keep on clicking, you eventually get to some fun facts about email, such as there are over sextillion ways to spell Viagra.
All in all, it's a comprehensive view of how much email Yahoo handles that's fun to poke around. Turn on your speakers for playful sound effects.