As the Roulette wheel spins and spins people try to come up with some sort of betting system by which to end up with more money then when they entered the casino. After all, that is the goal. But what are you meant to do when the ball could land anywhere? Where on the Roulette table are you meant to place your bets?
The Martingale System is normally the first roulette strategy which comes to mind because it banks on the fact that as long as your bet comes off you are going to be ok in the end. The problem of course with the Martingale System is that if you endure a long losing streak you will not be able to bet pass the upper table limits which are in place and you are looking down the barrel of some huge losses.
It might be feasible to use the Martingale betting systems in a tactical range with smaller bets as compared to the overall table roll, but using it consistently throughout the game is low percentage roulette . While the Martingale System might be more or less useful even on longer game streaks with high probability bets (and lower payouts) like the outer table bets, it becomes increasingly dangerous at less probable bets because of the law of large numbers (think of uneven distribution of the numbers on a short scale, such as a 40 game rounds).
All in all the risk that Martingale presents at any game, and especially fixed odds games like online roulette means you should be very cautious if you are going to use it as the possible benefits may not eventuate.