Clay Voorhees, Michigan State University (IMAGE) Michigan State University Caption Most US service workers are giving away free goods and services, costing companies billions of dollars a year in lost revenue, according to a first-of-its-kind study by Clay Voorhees, marketing expert at Michigan State University. Credit Michigan State University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.