playing with profit of course is a good strategy and safe. I always do this to keep my bankroll. so that I don't lose it all in an instant.
yes no doubt about this i am also in favour of playing gambling with profit, because through this way you are saving your own money, and if you are loosing after investing your profit then its mean that still your profit is safe.
Actually based on what I see and experience, it's very hard to spend only your profit as not all the time you start winning. There are times you are so unlucky that you will experience a cold losing streak and you feel to chase your loses so you can get back on track. I believe what a gambler should do is only learn how to limit their loses and stop when the target of winning is already achieve.