Nothing comes for free. If it is free, it probably needs you to spend much time or doing something for them to advertise their products or service. One example would be Bitcoin faucets, they are free but you can get very little money. The time should be spent on more meaningful stuff and that can let you earn more money.
when.... what about Steemit?
it's free and it fits to your description for Bitcoin faucets
While it's free, it requires your effort and devotion into this platform. You have to post interesting topics regularly or you will lose your followers. It's not free as there are hard work involved. However, I have to admit I enjoy doing so. I like this platform :)
I like this too.
but my hubby thinks it's sect :)