  The development of Internet technologies enables software developers to build
virtual worlds such as Massively Multi-Player Online Role-Playing Games
(MMORPGs). The population of such games shows super-linear growing tendency. It
is estimated that the number of Internet users subscribed in MMORPGs is more
than 22 million worldwide [1]. However, only little is known about the
characteristics of traffic generated by such games as well as the behavior of
their subscribers. In this paper, we characterize the traffic behavior of World
of Warcraft, the most subscribed MMORPG in the world, by analyzing Internet
traffic data sets collected from a European tier-1 ISP in two different time
periods. We find that World of Warcraft is an influential application regarding
the time spent by users (1.76 and 4.17 Hours/day on average in our
measurement), while its traffic share is comparatively low (< 1 %). In this
respect, we look at the World of Warcraft subscriber's gaming behavior by
categorizing them into two different types of users (solitary users and group
users) and compare these two groups in relation to the playing behavior
(duration as the metric) and the in-game behavior (distance as the metric).
