Shortly after Tony Shap began college, an older friend offered some career advice: The real money, he said, was in credit card processing. Shap took his friend seriously. He launched his own company, signing up customers by cold-calling nearby small businesses. When he made $30,000 in three months, he dropped out of school and went to work for a large credit card processing firm. Five years later, he launched PaymentMax, which made a then-outlandish promise: to pay merchants the next day. The business was a success out of the box, but things really took off when Shap decided to jump into the mobile payment market, in which merchants swipe credit cards on their smartphones. "It can get old working in an unsexy business where all you do is push money," says Shap. "The growth of smartphone payments has reignited my passion to go after new markets."