(Website is closed as of January 2019)
This website gives away cloud mining power on the same platform they sell from. It gives you a chance to get a feel of the system and it gives you about $20-30 /yr in bitcoin. Of course you can't withdraw until you actually pay for a paid contract. Those start a very low prices and lifetime contracts.
They have a referral program. Here is my link: https://micro-btc.com/register.php?referrer=KccIqwQHLlob
Here is a direct link with out a referral: https://micro-btc.com/