How? “Seven friends in ten days,” Facebook growth hackers repeated like a mantra in the early years, ahumming meditation that carried them from dorm room to nearly every corned of the world??2. If you or I joined the service and found seven friends in ten days, we would most likely stay, enjoying the benefits of the gated world, making it that much harder (impossible really) for friend number eight to wander somewhere else. Pretty soon, there was essentially nowhere else to go anyhow. The network magnetism worked so well that, as a result, Facebook’s speed- looping connection machine cut the famous “six degrees of separation” posited by Stanley Miligram - the number of leaps between any two people on the planet - to four.233 Network theorists who came after Arthur call these “rich get richer” systems “power law distributed” because if you line up all the firms in a digital industry you find the winners are exponentially - by a power of ten or one hundred - ahead of everyone else. They slip free from the average gravitational center of a normal bell curve that marks most traditional business. A normal distribution would shape up like a chart of people who own cars: 20 percent driving Fords, 10 percent Nissans and Toyotas, and so on. Or it might look like the distribution of height: Most men are between 5’7 and 5’11, but 50% are scattershotted at different heights. Network systems, however, can breed commanding winners. It’s not like 50% of online users are on the Internet and others are scattered across different systems. Users huddle into single winning clusters. It’s as if 90% of the world always bought a Ford; or 90% of people were exactly 5’ 11”. These systems run faster and better and more profitably because they are locked-in, gated by technology standards and by common connection. When we say that networks crave gates, this is the sort of gate we mean. If you had to look for your friends one-by-one on Facebook, Friendster, MySpace, and GooglePlus you'd exhaust