Every day PostRank archives almost 10 million engagement events (online consumers voting on stories, sharing links on Twitter, leaving comments on posts, etc.)
Each of those events is associated with a URL, which means that we have, in effect, a panel of tens of millions of users who give us the pulse on every story being shared and discussed across all the major social media platforms. A heaven for data geeks of all professions. 
To that end, PostRank is always researching, developing, and tweaking access to data, how we can analyze and present it, and, most importantly, how we can help customers use the data. Today we’re launching another powerful tool in our Data Services toolkit: the Domain Activity API.
Check out the PostRank Labs demo for a quick preview of the data. Type in any 3 top level domains, and we’ll show you their overall performance, as well as the top sub-domain performers for each one. Keep in mind, however, that the Labs demo only shows the tip of the data iceberg available to our Data Services customers!
Prior to now, you’ve been able to access all of the metrics data via our Metrics API (to find all activity with a specific URL), or the Feed Engagement API (to find all activity for an entire RSS feed, for some period of time). However, what if you’re also interested in bigger, macro-oriented trends? Curious if people are talking about content on your domain, or, perhaps, how your competitors’ audiences are engaging? Now you can satisfy that curiosity via our Domain Activity API.
Let’s have a look at an example. Ever wondered how WordPress, TypePad, Tumblr, and Posterous stack up against each other? (For Blogger stats, check the spreadsheet.)
First off, Posterous still has ways to go to catch up to the rest of the pack when it comes to user engagement. (And to be fair, the other sites have between 2 and 6 years’ head start.)
Both WordPress and TypePad attract a significant portion of on-site comments as part of their engagement, indicating that the “micro-blogging” phenomenon has far from taken over the overall media landscape, and on-site engagement isn’t entirely dead. On the other hand, Tumblr attracts a significant proportion of its traffic from sites such as Reddit and Digg.
Curious about these trends? Feel free to dig a little deeper into the live data, or download the spreadsheet.