nostrich had some really insightful points and questions about the new Directory:
The directory is being touted as a way to find blogs that are “gaining momentum”. But how does listing the most popular 7 blogs in a particular category help anyone except the popular people?Simply, Tumblarity isn’t a metric of popularity. We’ve tried to design Tumblarity to reflect how active and interesting your blog is at this moment. That means anyone (even someone brand new to Tumblr) can create something that resonates with the community and in turn bubbles them up to the top for people to discover.
If Tumblarity isn’t a metric of popularity, why is it named after the word popularity? Honestly, the URL is tumblr.com/activity — why isn’t it just called Activity?