What Hypnosis Can Do? Where and How Much It Can Help? 

First of all, notice the wrong title. Hypnosis cannot do anything. It's about the people. About the therapist and the client. Good therapist can do a lot, as well as a good client can do. 

Hypnosis can help. How much is another question. It depends on the issue you want use it on, on the quality of the product and hypnotherapist. Many variables come into play.

 
While hypnotic products like mp3's, cd's, tapes etc. usually only can take the generalized approach, a private session with a hypnotherapist can bring you personal attention and ensure that all the aspects particular to your case are addressed.  Shall you go for a tape perhaps, for a private session, or for both, it is the personality of the hypnotherapist that is the most important variable and determinant of the results achieved. That being said, it is also not the hypnotherapist always at fault when the results are not achieved, particularly with tapes and cd's - many people don't follow the instructions, or as it happens, their problems are too deeply rooted or unique that at their current level of experience, they can't manage it without the one-on-one help. Last but not least, big difference is in the succes rate between clients that go for hypnotherapy "because someone else wants me to change", "because otherwise I would be done in my job" vs. others that "want to change this or that very much" - I hope you can see the slight difference between these two.