  Tumblr, as one of the most popular microblogging platforms, has gained
momentum recently. It is reported to have 166.4 millions of users and 73.4
billions of posts by January 2014. While many articles about Tumblr have been
published in major press, there is not much scholar work so far. In this paper,
we provide some pioneer analysis on Tumblr from a variety of aspects. We study
the social network structure among Tumblr users, analyze its user generated
content, and describe reblogging patterns to analyze its user behavior. We aim
to provide a comprehensive statistical overview of Tumblr and compare it with
other popular social services, including blogosphere, Twitter and Facebook, in
answering a couple of key questions: What is Tumblr? How is Tumblr different
from other social media networks? In short, we find Tumblr has more rich
content than other microblogging platforms, and it contains hybrid
characteristics of social networking, traditional blogosphere, and social
media. This work serves as an early snapshot of Tumblr that later work can
leverage.
