I have a friend who is playing a roulette system online.

Basically he bets 1 dollar on either red or black and if he loses he bets 3, 5, 10 and so forth. When he wins he bets 1 dollar again.

I have 3 questions:

1. Is this illegal?

2. What is the chances of missing 7 times in a row?

3. Do you think its profitable given a 100 dollar max bet?