Some ad-hoc networks have no central registry and the only way to spread common data is to rely on each member to pass it along to their neighbors.
More typically gossip protocols are those that specifically run in a regular, periodic, relatively lazy, symmetric and decentralized manner; the high degree of symmetry among nodes is particularly characteristic.
Thus, while one could run a 2-phase commit protocol over a gossip substrate, doing so would be at odds with the spirit, if not the wording, of the definition.
The term convergently consistent is sometimes used to describe protocols that achieve exponentially rapid spread of information.
Suppose that we want to find the object that most closely matches some search pattern, within a network of unknown size, but where the computers are linked to one another and where each machine is running a small agent program that implements a gossip protocol.
Gossip protocols can be used to propagate information in a manner rather similar to the way that a viral infection spreads in a biological population.