Forget tech startups and stock picks. A Princeton economist's research reveals that many of America's millionaires built their fortunes through private businesses in industries most people overlook. Billionaire Rich Kinder did it with pipelines. Ray and Dana Chery are hoping to become the next generation of billionaires by betting on portable sinks. Their stories challenge conventional wisdom on how wealth is actually built. -------- More on Bloomberg Television and Markets Like this video?