The thing is that those "profits" are just the winnings, but most gamblers actually end up losing more than what they win.
It's a very common thing to hear stories from gamblers that only tell about their winnings.
They never tell about their losses, and that's a basically how people get excited about gambling.
I'll tell you a story that i heard as a girl, let's say a teenager. A family friend had the vice of real gambling and was convinced he was strong. He went far away, to Campione d'Italia to the casino to play hard.
The first evening he called his wife, very happy, he had won 10 million lire, which was a lot of money at the time.
The next night, the last one before returning, he dared too much and lost everything. He returned penniless and they had to migrate to escape debt and find another job.