Clay says the best predictor of longevity for a system is not to inspect the business model but to answer this question: Do the people who like the place/building/system/product take care of each other? Not just take care of the object of veneration but take mutual care of the fans?

We have always loved one another. We’re human, its something we’re good at. But up until recently, the radius and half-life of that affection has always been quite limited. With love alone, you can get together a birthday party. Add coordinating tools, and you can write an operating system. In the past, we would do little things for love, but big things, big things required money. Now we can do big things for love.