I have talked to several people who are using the Wikipedia as an ontology of knowledge. Surely there is much more data to be mined there. But what statistics exist about its operation? What trends there are that are indication of markets? How does that differ from other social media? The data is freely available. More In an article from Wired:
" ... There are websites, and then there’s Wikipedia. The internet behemoth boasts 30 million articles written in more than 285 languages, tweaked by 70,000 active editors and viewed by 530 million visitors worldwide each month. As mountains of information go, it’s Everest. Teasing out trends from the open source encyclopedia’s archives is a task few would even attempt. Yet Erik Zachte did just that.
Zachte used his statistical intuition to create “Wikistats,” an online statistics package that’s more than a trove of charts and graphs for data geeks. It’s the most direct measure yet of Wikipedia’s success in achieving its central objective: making the sum of all human knowledge available to everyone everywhere. ... "