There are many sites like Gambling and Casino websites where you are given bitcoins everytime you win on a gamble and other than this there are also some sites that pay you Bitcoin for simple works, spins, and games which are called faucets where you are given some part of Bitcoins each time when you spin or play that particular game. Now here there is very little chance that you are going to win because all their sites are automated by the BOTS and I don't think you can win over those BOTS easily and even if you are winning then you need to spend tons of time and efforts here, so better don't waste your time here.