  SinaWeibo is a Twitter-like social network service emerging in China in
recent years. People can post weibos (microblogs) and communicate with others
on it. Based on a dataset of 650 million weibos from August 2009 to January
2012 crawled from APIs of SinaWeibo, we study the hot ones that have been
reposted for at least 1000 times. We find that hot weibos can be roughly
classified into eight categories, i.e. Entertainment & Fashion, Hot Social
Events, Leisure & Mood, Life & Health, Seeking for Help, Sales Promotion,
Fengshui & Fortune and Deleted Weibos. In particular, Leisure & Mood and Hot
Social Events account for almost 65% of all the hot weibos. This reflects very
well the fundamental dual-structure of the current society of China: On the one
hand, economy has made a great progress and quite a part of people are now
living a relatively prosperous and fairly easy life. On the other hand, there
still exist quite a lot of serious social problems, such as government
corruptions and environmental pollutions. It is also shown that users' posting
and reposting behaviors are greatly affected by their identity factors (gender,
verification status, and regional location). For instance, (1) Two thirds of
the hot weibos are created by male users. (2) Although verified users account
for only 0.1% in SinaWeibo, 46.5% of the hot weibos are contributed by them.
Very interestingly, 39.2% are written by SPA users. A more or less pathetic
fact is that only 14.4% of the hot weibos are created by grassroots (individual
users that are neither SPA nor verified). (3) Users from different areas of
China have distinct posting and reposting behaviors which usually reflect very
their local cultures. Homophily is also examined for people's reposting
behaviors.
