  Animated GIFs are becoming increasingly popular in online communication.
People use them to express emotion, share their interests and enhance (or even
replace) short-form texting; they are a new means to tell visual stories. Some
creative animated GIFs are highly addictive to watch, and eventually become
viral -- they circulate rapidly and widely within the network. What makes
certain animated GIFs go viral? In this paper, we study the virality of
animated GIFs by analyzing over 10 months of complete data logs (more than 1B
posts and 12B reblogs) on Tumblr, one of the largest repositories of animated
GIFs on the Internet. We conduct a series of quantitative and comparative
studies on Tumblr data, comparing major types of online content -- text,
images, videos, and animated GIFs. We report on a number of interesting, new
findings on animated GIFs. We show that people tend to make animated GIFs
easily searchable and discoverable by adding more hashtags than other content
types. We also show that animated GIFs tend to go more viral than images and
videos on Tumblr. With more in-depth analysis, we present that animated GIFs
tend to get reblogged more and followed more from non-followers, while animated
GIFs have more recurrence of a post. Lastly, we show that the virality of
animated GIFs is more easily predictable than that of images and videos.
