Figure 4

Intermediate spreaders connectivity. Cascade size vs. average connectivity of intermediate spreaders $〈k_{\mathrm{sp}}〉$ (left: ‘grassroots’; right: ‘elections’). Non-instantaneous cascades are displayed, where the initial seed and its inactive listeners have been removed in order to dismiss the effect of the initial seed on the cascade size. There is a clear correlation between both magnitudes, although some unexpected behavior shows up: the existence of cascades containing ‘hidden spreaders’, users who are capable of generating large cascades despite not having hub-like connectivity. In both panels the function $y=(x+1)/N$ is drawn as a reference.