Regardless if you playing for fun, or playing for the profits, if you play beyond the normal level you are expected to play, and you get so involved, you can become addicted, same ways if you win or you lose in gambling you can still be addicted.
What matters is how you gambling, and not or what you get from gambling, whatever you do too much is already addictions, when it becomes uncontrollably done multiple times
The summary of this is "balance" and how important it is to exercise. Wins or losses, joy or tragedy, etc., can all lead to addiction; there is no fixed path to that state. This is why the practice of balance must be engaged to ensure that things are done in moderation regardless of the state you are in.
Now thinking of "balance," to maintain it, I think it goes back to discipline, because it will require discipline to maintain balance in gambling.