Perry Marshall is endorsed in FORBES and INC Magazine, and is one of the most expensive business consultants in the world. Clients seek his ability to integrate technology, sales, art and psychology. His reinvention of the Pareto Principle is published in Harvard Business Review. NASA’s Jet Propulsion Labs at the California Institute of Technology uses his 80/20 Curve as a productivity tool. 80/20 Sales & Marketing is mandatory in many growing companies.