Freespin is something that casino give occasionally to their members. But that will not for all members because casino will choose who will deserve to receive the freespin. Each casino will know what they will give their loyal members.
And who do you think really deserves such reward!
Obviously casinos will give rewards to their loyal customers. The more you play and the more you spend on the casino, the more likely you are going to receive some rewards (cashback) from them.
I'm not an expert, but I'm not afraid to try playing, at least it makes me happy and gain experience, a real man is not afraid of eternity LOL