Product review (5 stars): "A stranger is just a friend I haven't met yet"
With talk constantly of "working your network" and leveraging your friendships, we lose the importance of expanding our friendships beyond a comfort zone:  to strangers.  Strangers are intimidating, may not want to be engaged, but are valuable to expand your universe and world view.

Once I went to a conference (as a junior person) with some executives from my company.  The executives interacted with each other, and with some people who worked at another location for the same company.  I leveraged my contacts to meet others at the conference, and just downright introduced myself to people.  I was far better at solidifying new business contacts than people who had far more experience than I, only because I was more gregarious and wanted to meet others.

Gregerman expands on this concept very well, and points out the many advantages of dealing with "new blood" as opposed to the same old people.

Well written with good examples, "The Necessity of Strangers" is an important book for someone looking to expand beyond their sphere and learn from, and teach, others.