^ That could be the consequences that you may encounter in some gambling casino, you cant withdraw your small winning because there is a minimum withdrawal but I have an idea, it is possible that I can still withdraw my balance under the minimum withdrawal? For example, I have 0.003 BTC there but in order to reach the minimum amount of withdrawal, I will deposit 0.001 BTC so that I will be able to reach the minimum amount of withdrawal. Do you think this is possible?
Back then it was possible as I used to do the same strategy when I have a bit of balance stuck at a casino but like what Pmalek said, most gambling sites already have a rollover so you're expected to play the deposited amount.
There's also that one sportsbook that offers a faucet I think their site is called betja but I haven't tried them yet though.