I used to play dice in online casinos and apply the martingale technique. In the beginning, I had some profit but as the time went by I started losing and losing and I wasn't able to cover my initial bet.
Now I am trying something like the same but differently. I pick a big football club and I bet that it will lose. If I lose my bet, I double it and so on.
Martingale is not a good way to earn the easiest profit yet you can lose your funds faster than playing it with a smaller bet. Martingale is just good when the odds are upon you but not a good strategy if you are losing. It makes it worst in the long run so I wouldn't suggest that.
Just look for a better odds the team and bet some 60% of your main funds or so.
Martingale does work or not work depending on the luck of certain person. Ive tried it for how many times and the outcome do varries on how lucky i am on a particular day.
Back to topic, i cant still say that its the easiest way to make money thru gambling on whats being stated on op, small margin doesnt give you assurance sure win.