the result of feelings

The Nibbedhika Sutta: Penetrative (translated by Ven. Thanissaro) states the following: >"And what is the result of feeling? One who feels a feeling produces a corresponding state of existence, on the side of merit or demerit. This is called the result of feeling. What does this mean? If a feeling is either pleasant, unpleasant, or neither pleasant nor unpleasant, then isn't additional input required to determine merit or demerit?