  Information spreading has been studied for decades, but its underlying
mechanism is still under debate, especially for those ones spreading extremely
fast through Internet. By focusing on the information spreading data of six
typical events on Sina Weibo, we surprisingly find that the spreading of modern
information shows some new features, i.e. either extremely fast or slow,
depending on the individual events. To understand its mechanism, we present a
Susceptible-Accepted-Recovered (SAR) model with both information sensitivity
and social reinforcement. Numerical simulations show that the model can
reproduce the main spreading patterns of the six typical events. By this model
we further reveal that the spreading can be speeded up by increasing either the
strength of information sensitivity or social reinforcement. Depending on the
transmission probability and information sensitivity, the final accepted size
can change from continuous to discontinuous transition when the strength of the
social reinforcement is large. Moreover, an edge-based compartmental theory is
presented to explain the numerical results. These findings may be of
significance on the control of information spreading in modern society.
