Every startup in Silicon Valley wants to be the next Facebook, with its one billion users, or LinkedIn, which just sold to Microsoft for $26 billion. And why not? Their business model is a beautiful thing: platforms (also known as two- or multi-sided markets) are asset-light and make money by sitting between different parties, controlling the market and taking a piece of every transaction. Consider Care.com, which connects parents and babysitters who would otherwise have trouble finding one another, and just as importantly, ensuring the reliability of the other party. If Care.com’s owners earn a hefty commission, they’re doing so by making the world a better place, one babysitter match at a time.