Cornell University Professor Jon Kleinberg drew in a standing-room-only crowd with his lecture on Diffusion and Cascading Behavior in Complex Networks at Yahoo! Research on Thursday, August 3, 2006. Kleinberg focused on large social networks and the "cascading behavior" that results as knowledge is passed within communities.

He gave real-world examples on how social communities are formed, and the opportunity of disseminating information through the interaction of these communities in the online world. Individuals are empowered to share information with their friends, family and colleagues – individuals’ decisions to purchase a product, for example, are strongly influenced by the recommendation of their social networks. Kleinberg also discussed how cascading behavior affects the online world, including the diffusion of topics in blogs and emails.