Luca pointed to a paper by Chierichetti, Lattanzi, and Panconesi, which has an amusing comment in the last section (I don’t want to spoil it).

The paper itself is interesting, of course. Conductance often appears in bounds on mixing times for Markov chains, but the rumor spreading problem is a bit different than the consensus problems that I have studied in the past. A nice quote from the introduction:

Our long term goal is to characterize a set of necessary and/or suffcient conditions for rumour spreading to be fast in a given network. In this work, we provide a very general suffcient condition — high conductance. Our main motivation comes from the study of social networks. Loosely stated, we are looking after a theorem of the form “Rumour spreading is fast in social networks”. Our result is a good step in this direction because there are reasons to believe that social networks have high conductance.