Marc Louvion spent years waiting tables at $10 (£7.90) an hour, living with his parents in France, convinced he was one idea away from building the next billion-dollar company. He was wrong. Repeatedly. The 32-year-old French developer, known online as Marc Lou, told Starter Story that he failed roughly 30 startups before landing on a product that now generates over $1 million (£790,000) a year with zero employees and profit margins of around 91…