Very very little. The amount you make is very small relative to the amount you can lose. In exchange, the probability that you will lose is very, very low.

It's like a lottery in reverse. With a lottery, the amount you lose is very, very small and the amount you can win is very, very large. But in exchange, the chance that you will win is very small. With a progressive betting system, the amount you win is very, very small. And the amount you can lose is very, very large. But in exchange, the chance that you will win is very high.

And with both, because the house has an edge, the house's expected profit will always be positive and the player's expected gain will always be negative.