Six Rules to Becoming a $1.7 Billion Startup

Weather watchers refer to supercells as storm clouds with the potential for severe weather, but the Finnish company Supercell is the $1.7-billion gaming company behind "Clash of Clans," the top-grossing iPad game in 122 countries last year. It stands out not for any dangerous element, but for its huge success. Inc. magazine shares six lessons businesses can learn from the success of Supercell.