Over the last three years, I’ve been working on understanding social collaborative behavior, and in particular at LinkedIn, Viral Loops. Interaction design is key to an applications ability to promote itself. In this short session, I’ll focus on the critical comments of defaults, sharing mechanisms, updates, notifications and even SEO as holistic elements of a viral system that is currently driving the popularity of social networks and social media successes everywhere. I’ll talk about the underpinnings needed to devise a successful social system as well, touching on identity, reputation and relationships in digital communities.