Martingale only works for very short term and if you have luck ,you will lose faster if you play at site which have bigger house edge
even in short term you can easily loose, one i got 10 looses in a row after rolling 3 bets on primedices new account, the best is not to use martingale
The best is not to gamble.And if you are damn serious about gambling than I think martingale is the best method(only for short terms) and the worst method(for long period) too!
Check out this video,
https://www.youtube.com/watch?v=tmlscCK7E5cIt will explain you all the cons and pros of martingale.
Martingale works but not every time I have 16 loses in a streak and out of money so not able to do this again