@silveryslade 
What sort of rituals do you undertake? Is it a graded organised system? Are they designed to bring you closer to Satan? How does this feed through into your daily life?
@Ibelieveinghosts There is a certain vibe/power that's released by doing something taboo, acts of blasphemy or taking blood from oneself etc.
Some of it is about getting real-world results or personal power. (Practical Magick or initiation.)
A lot of it is like any other religion I think- people pray (or work a ritual/magick) to their god for a particular outcome, or to be closer to their god, for comfort in difficult times.
Some groups/systems have levels and others don't officially, but initiation is a constant process we all experience through life- you learn new things about the world etc.
The aim can be to make oneself a stronger person better able to deal with adversity, to achieve certain real-world goals. Some people want to be a better conduit for the will of Satan on earth (I'm too lazy for that.) 
So in some ways- following Satan's Will for you, or praying for comfort etc, it's similar to Xtianity.
The Goetia is another thing I like, but I do a basic version- just give prayers and offerings to various demons.
@RockinHorseShit I find a lot of 'white' witch or 'white' magic groups can be overly cautious/'superstitious' (omg you mustn't do X, you might die or go mad or whatever.) I've been involved with most things over the years to one extent or another, starting out with paganism/Wicca.
It did take me a while to get my head round the idea of blood offerings though, as I thought of it as self harm. I learnt about it on OFS demonolatry forum and I balked at it for a bit. But if someone just takes a pinprick of blood with a diabetic pen as they said to do, it's not really the same as they're not really at any risk (if clean) and it doesn't even really leave a mark. People who have to test their blood may do it several times a day. Or of course people can use menstrual blood.
The results are no more unpredictable than in any other type of magick, maybe less so.