It is really up to the person who is playing if he or she use his or her profit. But I do not urge on using the profit because that's my win. If I lose those I will go home without any money. But what I'm doing is if I already won I will go home. So winning something that exceeds my first money is equal to my house haha.
I always prefer to play with the winning amount. Here I have certain regulations that if won I used to save half the amount in a separate wallet that's used for saving from gambling. With the remaining half I used to play. It gives the stubborn mind to predict more precise as the failure won't affect me, as I have a small winning already.
I cannot apply that to myself because most of the time I lose and if ever I win I go aggressive because I am feeling that if I am lucky I should win more.
Although I have that kind of attitude but I still feel safe because I only do it for fun, whatever amount I bet is sure the amount that I can afford to lose, that's gambling you can never predict the correct outcome all the time so just bet based on budget.