Well it really works if you have the money for it as if you can't continue doubling your bet if you will run out of cash at the end. This strategy will always require a small amount of profit assuming that you will win in the 2nd, 3rd, or so on as long as you have money for it. The strategy here is always to start small as you are not expecting to win big at your 1st bet. But it is just my personal kind of play and there will always be a different kind of definition on what amount is "small" for them, as it will always depend on how much capital is the gambler willing to bet.