Depends on the chiropractor. Any chiro who tries to set you up on an extended "contract" is a crook. A good chiro will not make outrageous claims about "curing all your ailments with spinal adjustment."
I'm a huge believer AND a huge skeptic. I will not see a chiro who tells me I have to come in multiple times a week for months on end, especially if he hasn't examined me yet. I use chiropractic, occasionally, as needed for migraines (I have a rotated atlas- top vertebra, it's clearly abnormal on xray, even without anyone pointing it out. Makes the cranial foramen magnum look like a lopsided ellipse instead of a near circle.) It works for me, but I do NOT have to go all the time, just when I feel certain symptoms, and can palpate a knot in one area on my neck.
I also have clients who occasionally see chiropractors. Sometimes I send them for an adjustment because things feel "wrong" and they are having a spasm in the area. Usually one or two adjustments corrects it. I also have clients who have gone for adjustments every week for years. They are in really bad shape, I believe because of the over-treatment.
So very mixed feelings. If your gut tells you the chiro you are seeing is a crook, run away. Anyways, he fired you because you couldn't be sold oceanfront property in Arizona. Good for you.