Social design ain't your daddy's web design.  It differs in many ways from the old school study of pure omnibus interactions.  Social Design begins with sociological trends of tribes (your audience), then takes into account their behavior and more importantly their passions.  Most successful social brands are finding direct responses when they facilitate a tribal passion through pretty basic functionality. 

Think you can do it without their passion?  Think again. 
If you are not ready to be passionate about what a tribe is passionate about, this is a waste of time and money for your brand.  How do you expect to have a meaningful conversation within a tribe if you have nothing in common with them? When you listen to your audience and unlock their passions then and only then can you have a place in their conversations. (This is where I typically do the message is the medium dance.  I promise you it's a whole dance.)

As I was working on a conversation starter for one of our clients, I stumbled upon this fantastic presentation.  This is one of the most tribal-centric presentations I have seen on developing social software.  Each part focuses on a specific problem in developing social media
platforms.  This sociological and behavioral approach takes on the major hurdles in a usage life cycle, which are the stages people go through as they use and adopt
software over time.

This methodology can be used in many aspects of the things we create as digital agencies. The tribal insights dispel many digital design myths. Designing For Social Traction  makes the design challenge clear for anyone creating in the social space.