If you can resist the temptation and withdraw your profit [or half of your balance, regardless of it being profit or deposit] then it's a better way IMO, the issue is that if you lose the remaining balance the odds of the player re-depositing the profit is quite high..
That is where almost 99% of the people who use gambling to make money usually lose, because if they win they dont call it and satisfy with amount that they won they just keep going form more they are too greedy until they end up addicted to it and they start losing and they keep going in until they are left with nothing.
yes in fact most of the people have the same strategy and mostly they play on the winning amount also and continue until they lose their own money in gambling including the winning amount. to me i try my best first to withdraw my investment money in gambling first and then continue to play with the winning amount and through this way i just save my own money in gambling.