They are all thought forms manifested in reality. An artist when creating a drawing automatically looks within for an idea or "Thought form". A Musician looking for the next hit also doesn't "Think of the song" but rather listens to energy forms that will give him a motion (implied as a direction of travel) of inspiration.

Books, Audio, Movies are all attempts at re-creating a vision that came to the architect of that idea. By the time the idea is saved as a book, audio, or visual medium, it only represents a fraction of the actual totality of that energy form.

Now, Intent is also a large component of an idea, something like a feeling tone representing intent. If the intent is clear, be it good or bad (neither being relevant here), it is embedded in the "Consciousness" of that medium of transfer (book, tape, DVD)

When we pick up a book, audio, or DVD, the first attractor seems to be the Intent energy that is part of that energy manifestation. It is like on a consciousness level we are quickly scanning through the headlines. And consequently if we begin with our feelings as a guide, we gravitate towards something that feels right (that is an energy match to what ever is the reason for that search).

This is why, often you will pass by a book you are somewhat interested in, but some thing gets in the way & you never get it. Then long after the interest has passed you stumble on the book & upon reading it, you discover that, If you had read the book earlier, the timing would have been wrong. Only by waiting longer were you able to fully appreciate the knowledge form that book (energy form).

Now here is the amazing part. When you start reading the book you don't get the information from the logical process of reading & understanding. Rather, you are actually downloading from the original energy organization that gave rise to the capture of it in a book form.

So, although, in capturing an idea into a medium, most of that original information is not fully transferred, when the reader reads the book he/she touches base with the same idea in it's original potential energy form, allowing the reader to understand the meaning from the original source, the same source that initiated the creation of the book, CD, or DVD etc.

So a book, for example, actually transfers much more than what is on the page.

Well at least that's my take on the question.

Good question. I think it's probably a combination of both. If the principle contained within the book or recording has no reputable value then I would hazard a guess that it would be less effective. However if we believe something is going to work then it will become real for us - the placebo effect. Our world is created from our beliefs but those beliefs can also be changed if we put " sound effective principles " into practice.

Sometimes, books, audio books and other devices work because they help to generate a positive, good feeling and/or vibration that gets the manifestation train moving as you look for reasons to feel good, thereby causing a shift in your energy and vibration.

It's about allowing, and allowing is caused by focusing on what you do want.

All the best to you.