Gossip protocols are a family of protocols for (probably) disseminating information to (very likely) all nodes in a group, such as a distributed system. In the simplest version, each node keeps a list of all of the nodes in the group. When a broadcast is required, it sends the information to some set number of neighbors. You can make the probability of complete saturation arbitrarily close to 1 by doing more and more rounds, at the cost of duplicated transmissions.