As a gamer I am well aware of the concept of "Noob Farming". But it could also be applied in the content and publishing world.
The most fruitful harvest an expert can bring in is if they farm fresh noobs. People who are at the beginning of the learning cycle are always more hungry and more plentiful because most do not level up.
The art of providing the most basic level of information in a particular niche is incredibly rich in vitamins and minerals.
But it is very hard for someone who is expert in a niche to bother themselves with planting, cultivating and harvesting noobs. Those who can are never going to go hungry.