  Cooperators forgo their interest to benefit others. Thus cooperation should
not be favored by natural selection. It challenges the evolutionists, since
cooperation is widespread. As one of the resolutions, information spreading has
been revealed to play a key role in the emergence of cooperation. Individuals,
however, are typically assumed to be passive in the information spreading. Here
we assume that individuals are active to spread the information via
self-recommendation. Individuals with higher intensities of self-recommendation
are likely to have more neighbors. We find that i) eloquent cooperators are
necessary to promote cooperation; ii) individuals need to be open to the
self-recommendation to enhance cooperation level; iii) the cost-to-benefit
ratio should be smaller than one minus the ratio between self-recommendation
intensities of defector and cooperator, which qualitatively measures the
viscosity of the population. Our results highlight the importance of active
information spreading on cooperation.
