I would consider myself a Spiritual Satanist(shocker) and I have to disagree with A: calling Satanism a religion(but then, Laveyism might as well be one.) and B: That it's logical. The whole point of Satanism, is the bond with the serpent of knowledge, the light bringer Lucifer. Laveyism completely eliminates that intimate connection and just gives you a support structure for athiests longing for some kind of spiritual connection.
Satanism(particularly Spiritual Satanism), differs from a religion in that we owe no allegiance per say to Satan. I do not "pray" for his mercy, nor do I feel the need. Rather, it's an intimate Spiritual Relationship, no different from what you'd have with a significant other. That intimacy, that bond and that trust is something that cannot be found in the religious context. No matter how close a Christian may say they "feel" to God, they are the subordinates of Jesus and the Cross. In Spiritual Satanism, the family of Satanists and Father Satan himself are all one and equal and bound by love and self-empowerment.