I have a friend that is one. He adjusts me fairly regularly, but irregularly. HAHA.
If I see him 3 times a week, I get adjusted 3x. If I see him once every 2 weeks, I get adjusted 1 every 2 weeks. Since it's free..... I can't complain or expect a steady schedule.
Personally, I feel just as good when someone walks on my back and cracks everything under their feet. You can't fall for that crap about chiros being able to do magical shit like improve your memory, cure digestive problems, etc...