6. Xavier Helgesen and Christopher “Kreese” Fuchs

Company: Better World Books

The duo from University of Notre Dame started the company in 2002, largely based on their experiences in the Robinson Community Learning Centre. “Better World Books has become a full fledged socially and environmentally responsible business that sells reused or recycled books, while donating money and books for non-profits,” says Forbes. With over 6 million books donated and 85 million reused and recycled books under circulation, the company has made $55 Million revenue for year 2011.