•In scale-free networks, there is no threshold for virii to cross, according to Pastor-Satorras and Vespignani, in Aug 2000. This is because of the hubs. •You don’t need to know exactly who the hubs are—Zoltán Dezsö showed that ANY preferential treatment restores the threshold for infection. So if you’ve got something to sell, sell to those likely to be hubs.