"Information"
Radio, movies, TV, internet, twitter, and data-intensive services like finance, insurance, and health care -- part of second stage service growth. Even Henry Ford's mechanical marvel has morphed into rolling computers with complex software backbones -- millions of lines of code.
A 21st century joke is that out-of-work manual laborers become contractors. Out-of-work professionals become consultants, and if they are entrepreneurial, they invent a new software package.