Yesterday I earn in gambling is 0.1 btc
and today I lost 0.2 in poker and sport betting.
That is the reason why no one say exactly say if how much they can earn in gambling because if you win now you will lose again later and in place of getting profits you will pick up loses in it.
you are right, people will always lose money in a longer run thats why i stop gambling after a better run in order not to lose a lot