The first time Karl Nobert used Craigslist, it was to sell his old Audi. A teenager from Philadelphia took the train down to Union Station, test-drove the car out to Tysons and paid cash on the spot.
Craigslist, the internet’s dominant source of online classified ads, made news in June when it sent a cease-and-desist letter to PadMapper — a popular apartment-finding service that combines ...