Different kinds of social graphs can reveal how
users connect and interact with each other.
However, due to the limited information that the
graph can represent, various types of users’
activities cannot be characterized (e.g., time
duration of browsing a profile). An observation
from network operators can monitor such information
easily, and interpret how users use OSNs
better. Furthermore, for ISPs, they have strong
incentive to get better understanding of how the
traffic pattern between end users and OSN sites
will evolve, and take optimization actions according
to the distribution and activities of OSN
users. In this section, we review OSN user behavior
study from the perspective of network traffic
analysis.