It's not a proper way to learn any language, trust me, and the price is laughable. Rosetta Stone uses a method which was nothing but a fad based on incorrect assumptions about the way people learn. It's a confusing and frustrating waste of time. It might be okayish for Klingon, though.
Living Language uses actual workbooks, supplemented with Audio CDs, and is 1/10 the price. You'll learn enough from them to start reading and listening to simpler material, and using vocabulary builders. They're also easy to refer to later.
Human Japanese is something you should definitely look into for learning Japanese. Tells you a lot about the culture too, and is written in a nice, friendly and conversational style.
If it does not work then why does virtually every business and the U.S. military use it? I am not argueing that itis the best way (as I do think it is impossible to properly learn Japanese from it) but I think it works fine for Latin based languages