This is an interesting article on information diffusion over online social networks and its effects on other disciplines such as marketing. The key points from my perspective are:
* The structure of the social network plays more important role in the information diffusion.
* Online information does not spread as simple as a viral transmission. People often wait until a number of friends or trusted sources have adopted and promoted this information.
This article reminded me of some thoughts I had a couple of months ago for the difference in cascading effects between a "real" social network and an online social network. During that period there was the following "trend" on Facebook: everyone should have as profile picture, that of their favorite cartoon. Within one or two days almost all my friends (along with a large portion of the whole network) had adopted this trend. The analogy in a real social network would be everyone to wear a costume of their favorite cartoon. From my point of view that would never happen (or at most very few people would follow it). Even though this is an extreme example, I think that it can stimulate interesting interdisciplinary research on the differences between a real and an online social network with a focus on cascading effects and the "strength" of interactions.