Technological diffusion as a social contagion problem

One question relating to social networks that really interests me is that of social contagion, that is, to what extent is the structure of a social network conducive to the spread of a certain social phenomenon. Consider iPods (my favorite example). Clearly, the iPod takeoff is related to its technological merits (inventive user interface, storage), but that doesn’t explain the whole story. Using an iPod is also a social performance, and I suspect that to fully understand its ubiquity one needs to think of it also as a social contagion phenomenon.

‘Contagion’ implies a disease-like diffusion, but some (eg. Watts) make a clear distinction between how disease spreads (one’s likelihood of being infected is linearly related to the number of infected others one is in contact with) and how social processes spread (in this case, it is the proportion of ‘infected’ others that affect one’s likelihood).

But social contagion models are crude. They don’t distinguish between people or between excitatory and inhibitory ties, and they attribute perhaps too much importance to the network structure.

I am looking for ways of refining social contagion models. I am particularly interested in explaining technological adoption as a form of cultural diffusion. Data is an obstacle here: in the iPod case, how do we get access to information about people’s ties and adoption patterns over time? I think that the internet can make this question more amenable to research. For example, thinking about the proliferation of blogs as a social contagion phenomenon (people copy others who are socially ‘close’ to them). Any ideas how to operationalize this question?

I also think social contagion can be interesting in other types of cultural diffusion, for example in the adoption of economic behaviors (where rational-action theory doesn’t give a satisfactory explanation), political positions etc.

Looking forward to hearing your thoughts on how to translate this into a concrete research idea.

Amir