Hats off to Mark Zuckerberg and the entire team at Facebook.  They are managing that most impressive feat of innovating at scale.  They are also incredibly ambitious in what they want to accomplish.  The goal seems nothing short of one identity and one graph to “rule them all."  With over 400 million users worldwide and a sign on system that is being widely adopted this ambition doesn’t seem crazy.  Especially when you layer on top of this the possibility that soon many of these users might have Facebook currency that could be used by sites to implement 1-click purchasing (and by venues to enable RFID based payments via Facebook presence).

But I see at least one flaw with this plan for domination.  I simply don’t believe that there is a single social graph that makes sense.  I may very well follow someone’s booksmarks on del.icio.us that I don’t want to have any other relationship with.  Or take the group of people that I feel comfortable sharing my foursquare checkins with – these are all people I trust and would enjoy if they showed up right there and then.  That group in turn is different from the people I work with on Google docs for various projects which is why I would be nervous about using the Microsoft docs connected to Facebook.  Trying to shoe-horn all of these into a single graph is unlikely to work well.

As a little historical aside.  There is a bit of a personal irony in the huge noise around the Facebook "Like” button.  Yahoo could have had this in 2005 following their acquisition of del.icio.us if they had started to promote it to their users and to content sites!