“Sex sells” does little to explain the multimillion-dollar profits generated by the underground commercial sex economy. From high-end escort services to high school “sneaker pimps,” the sex trade leaves no demographic unrepresented and circuits almost every major US city. A landmark study funded by the Justice Department estimates that the underground sex industry in each of seven U.S. cities generates between $40 million to nearly $300 million a year. Hari Sreenivasan of PBS Newshour speaks with the lead author of the report, Meredith Dank of the Urban Institute.