LMFAO. To all of you claiming this is a gambling site and/or Bitcoin mining/staking/using is illegal, please read on (or if you'd like to know how they're used).
By visiting the site and rolling, you are joining many others in a BTC pool. The people actually mining the Bitcoins are other people in the pool and possibly the site managers (who have the tools to mine Bitcoins thanks to the advertisements on their page). Bitcoin mining is 100% legal, and this isn't even considered mining.
The Bitcoin (BTC) is an internationally recognized currency that has a strong stigma placed on it due to its historical use in purchasing products in the Silk Road. It's evolved from that state. In fact, many top investors advise purchasing/mining/rolling for Bitcoins due to their rapid increase in value. The BTC is a currency that cannot be regulated by any person or government, thus explaining its high demand.
To cash in the Bitcoins earned, go to Coinbase.com, set up a wallet, and use the address given to you by the site to register an account on Freebitco.in. Remember, no e-mail is necessary for registration, only a Bitcoin address (provided to you when signing up for a Coinbase wallet) and a password. As you make more and more BTC using that address, the coins will automatically be deposited in your Coinbase wallet every monday. But remember, there is a minimum to a BTC amount that can be deposited (I believe it's .1 and above, IIRC). You can then send your earned Bitcoins through Coinbase's "Send payment" method to other users' Bitcoin addresses, and in return, they will send you money in your preferred method (this varies depending on which people you're dealing with, I usually get paid via PayPal).
Good luck to all of you.