With Freebitco.in website you can earn free bitcoins every hour by clicking the roll button. It is the best faucet site on the internet. If you do not have any referrals (which can speed up your BTC earnings quite a lot), you still have a chance to increase your balance. My strategy is as follows: Disable collecting lottery tickets first, so you will have more REWARD POINTS (RP). Take Reward point bonuses as soon as possible, so you have at least 1200 RP + 1600 RP to take your first 500% FREE BTC BONUS. So once per week you can multiply your basic free roll payout 5-times for 24 hours.
Please note that the FREE ROLL is the lowest guaranteed earning! With some probability, you will get 10x, 100x or 1000x payout from time to time (numbers 9998, 9999, and 10000 are very unlikely to roll). Also you can try MULTIPLY GAME but be aware not to play too often and risky because you can lose everything. (The site states that the game is provably fair but you know... :))