It's a bitcoin faucet, and it is a literal trickle of bitcoin, but it costs nothing. Once an hour you can roll and win whatever amount, most of the time it's the minimum, but I get some amount over that once or twice a week. I also transferred in a small amount of bitcoin from my wallet because if you keep above a certain amount in their wallets you earn interest. I did a day's worth of research on faucets and this one is one the oldest and has a minimum of negative reviews. I don't bother with their cloud mining or lottery.