I have been using it for a little less than 1 month, and I don't honestly know how they are going to rip me off. You don't have to spend any money on them and if you are patient (or have a lot of friends) you can eventually get a withdrawal. In my opinion, so far, the only problem is the length of time until I have an amount withdrawable. They give me like 2.xxxx satoshi in bitcoin. 0.00000002.xxx