My first entrepreneurial venture in the so-called “sharing economy” happened accidentally. It was 2009, and I had just moved to Cambridge, MA to start at MIT Sloan. I brought my car with me because I was sure I would need it. As it turned out, the only time I used it was to go grocery shopping; mostly it sat idle. Word got around that I had a car, and I soon found myself fielding requests to borrow it from friends. One suggested I charge for the privilege.