  There has been a tremendous rise in the growth of online social networks all
over the world in recent years. It has facilitated users to generate a large
amount of real-time content at an incessant rate, all competing with each other
to attract enough attention and become popular trends. While Western online
social networks such as Twitter have been well studied, the popular Chinese
microblogging network Sina Weibo has had relatively lower exposure. In this
paper, we analyze in detail the temporal aspect of trends and trend-setters in
Sina Weibo, contrasting it with earlier observations in Twitter. We find that
there is a vast difference in the content shared in China when compared to a
global social network such as Twitter. In China, the trends are created almost
entirely due to the retweets of media content such as jokes, images and videos,
unlike Twitter where it has been shown that the trends tend to have more to do
with current global events and news stories. We take a detailed look at the
formation, persistence and decay of trends and examine the key topics that
trend in Sina Weibo. One of our key findings is that retweets are much more
common in Sina Weibo and contribute a lot to creating trends. When we look
closer, we observe that most trends in Sina Weibo are due to the continuous
retweets of a small percentage of fraudulent accounts. These fake accounts are
set up to artificially inflate certain posts, causing them to shoot up into
Sina Weibo's trending list, which are in turn displayed as the most popular
topics to users.
