As another point to add here: the placebo effect occurs because people believe the treatment they are being administered will work. Whatever it is -- be it a sugar pill or ayurveda -- if you believe it will work then the placebo effect occurs.
This is important because it means the placebo effect also exists with real medicines. Take chemotherapy as an example, and compare it to homeopathy. Yes, if the patient believes the treatment will work, homeopathy offers the placebo affect, but so will chemotherapy -- and chemotherapy also actually does something in the process. Here is a simple formula to explain what I mean:
If you believe it will work:
Alternative medicines offer the placebo effect.
Medicine offers the placebo effect, and also offers real, medicinal effects.
If you do not believe it will work:
Alternative medicine does nothing.
Medicine still works, but without the placebo effect.