The payment processing giant still has a bright future.Over the past three years, Mastercard's (MA -0.42%) stock has rallied by more than 40% as the S&P 500 advanced by about 25%. The payment processing giant impressed investors with its robust growth, wide moat, and resistance to economic headwinds.But will it keep rising over the next three years?How does Mastercard make money?Mastercard and Visa are the two largest card payment processing companies in the world, but neither of them issues any cards. Inst ...