I don't know that there need be a hard distinction between "saturation" and "possible" readers.
It seems that in my own experience, my (fiction) reading is highly dependent on my mood at the time; whatever I might be going through personally influences
what I want to read, and, subsequently, what I want to do with the story.
There are times when I desire to "escape" from RL as entirely as possible for a brief while, to recharge spiritual and emotional batteries. At those times I seem to also look for encouraging ideas from the book. At those times I go for "immersion", with Tolkien being a common choice. Rowling is another example of this. For this to be effective, the story-world must be substantially different from RL.
The other side of the coin is the "possible", in which I might want something closer to reality, maybe to more imagine
myself in the situations on the story.
For this I have the original Ian Fleming James Bond novels, and the complete Sherlock Holmes collection. I guess what I want there is a measure of escape, tinged with the faint hope that some qualities I admire in the book's characters might grow in me.
Or maybe all this is just the coffee talking.
