You walk into a casino, and you play roulette.
You bet
$10 on black,
lose
$30 on black
lose
$90 on black
lose
eventually
black comes out and you win.
I think the only thing stopping you would be the table limits?
I think it'll be true if only you had unlimited/huge bankroll. You never know what next result be, you can win within 4 bets, sometimes it could take you 10+ bets to win.
i'm not sure but i think table limit is around $5k, that means you can make only 6 bets. for a small profit it's not worth the risk.