The true believers won’t stop until they’ve remade the world. Some of it will be thrilling. Some of it will keep us up at night. [...] What Silicon Valley loves most isn’t the products, or the platforms underneath them, but markets. “Figure out the business model later” was the call of the early commercial internet. The way you monetize vast swaths of humanity is by creating products that people use a lot—perhaps a search engine such as Google or a social network like Facebook. You build big transactional web platforms beneath them that provide amazing things, like search results or news feeds ranked by relevance, and then beneath all that you build marketplaces for advertising—a true moneymaking machine. If you happen to create an honest-to-god marketplace, you can get unbelievably rich.