There are some systems currently for sale on e-bay. They use a trigger number. After the trigger number falls in then you bet on certain numbers for a certain number of spins until one turns up and you win. Each time you lose you increase your bet. Alleged winnings of £20-£50 per hour. After you win you revert to no-lose betting (except if 0 turns up) and wait for your trigger number to turn up again. However, you are limited by the maximum bet of £100 per spin and the staking method of the roulette (only goes up in £1 per number after the first £1 bet on any particular number).
The system, to my mind, is a simple increasing bet progression. The two trigger number systems I am aware of (one for Ladbrokes, one for Coral), on a perfectly unbiased wheel, will win for 99% and 96% of the time after the 'trigger' number according to my calculations. You win small amounts for that 99% and 96% of the time. However, when you lose, you lose big time, all your winnings and more.
The seller alleges that the chances of losing are nil on one system, and extremely rarely on the other system and that consequently, ultimately, you will win. I'm not convinced. It doesn't look like the Holy Grail of software roulette to me and you will simply need to play the system thousands of times to statistically prove that it works (the seller says he has played it thousands of times, over a 4 year period.....).
Dangerous. I won't be retiring just yet.