I had heard of this book some time ago. I was at a friend's party and about half the people there had met through me. Marshall said I was what the book calls a Connector, someone who provides relationships between people (it's a compliment although I think I'm closer to a Maven, someone who provides information and aid to others). The theory is that a few seemingly insignificant events or people cause massive changes (tipping points) in the course of events and Gladwell provides various examples (the reduction of crime in NYC and the rise of syphilis in Baltimore) of the principle in action--which he equates as "epidemic" spreads. It is very interesting and I wish the audiobook I had wasn't abridged as I am not 100% convinced by the argument, and maybe more examples would convince me that little things can make as big an impact as having a lot of money or being lucky. See Cej's review here.