The Economist piece on the PNAS paper by Onnela and Reed-Tschochas seems to have further stimulated just the kind of cascade of interest among business readers this week that the study at its hear actually describes. I keep tripping over pieces online and off.
If you haven't read it you should - some interesting new angles on social influence (and a magic number - 55!).
Any article abstract that starts like this, deserves your attention
"Social influence drives both offline and online human behavior. It pervades cultural markets, and manifests itself in the adoption of scientific and technical innovations as well as the spread of social practices"
But what I really love is the way the Economist readership go overboard a. to deny they use social learning [the Economist being after all the ultimate enlightment organ of independent thought] and b. disparage it using animal metaphors. One after another....