Simple Question, probably not so simple answer?

I have my own theory, but it is just that Theory, maybe some of you with more time in the field (so to speak, or should i say time by grow bed) have a better one, or different one.

My observations:
People who are making a living with AP ( or claim to be, no I am not skeptical, ok maybe a little) as far as I can tell are not just relying on the income from the produce and/or fish. The people I see, who are profitable are selling equipment, selling how-to books, selling consultations, selling seminars, etc. I am not saying there is anything wrong with any of this, just stating what I see.
Is there money only in the produce, if there is no fish market in your area, or the fish sell at a loss? I think it probably goes without saying there is no money if the fish are your only market and you are throwing your produce away?
Assuming an alternative income is needed to supplement the produce and fish? Is there sufficient room for more people selling equipment, selling books, selling seminars and training in AP??
Do not get me wrong, I think AP is a good thing, so far I see a lot of potential for a business profit, but I am a realist. I personally do not see a profit only selling the produce at a profit and the fish at a break even or slight loss (this seems to be the general plan of those I have talked to) without bringing in another income stream from some of the other things mentioned.

Maybe I am looking at this the wrong way, but I see the profit in AP in the support mechanisms, such as building systems, greenhouses or giving training, seminars?? Of course you still need a commercially viable farm to convince people it all works and you know what you are doing.