You can become a billionaire with anything — from collecting garbage to selling Beanie Babies. The point is to figure out what makes you unique and valuable to the customer. “As long as you're solving an emotional or financial problem for somebody, you can make a lot of money,” says Robert Blackwell, Jr., CEO and founder of several companies including Killerspin and Quant16 (formerly EKI-Digital). Robert’s been building companies since he was eight years old, when he was selling gum in school. Although he was, as he describes, “a non-dangerous delinquent” who didn’t take well to school — a common thread we see among founders — he’s always been an uncanny problem solver.