The mere existence of the idea written down will cause a shift in the universe, reverberating across reality until someone, somewhere, writes the story. It matters not if anyone reads the idea, or if the idea is even written somewhere it can be read. Its mere existence is enough. Thus is the way of the fic. It can even echo back through time, so that the idea that spawned the existence of the story is thought of after the story itself is created. Causality has no hold on something as powerful as An Idea For a Fic.
Case in point, my asking for a fic where Mouse Protector is stationed in BB and mentors Taylor resulted in the creation of
A Moth and a Mouse a week before I had the idea
.