Remember the feedback

No feedback after user's action causes frustration and insecurity, a sense of lack of control. It is because of our brain structure (see: reptile brain). We, humans, work like that. 

We need feedback to have the ability to learning. We need to feel we can control.

You lost the user if he/she feels insecure when something goes "wrong" when something seems to not work. 

A user expects some interaction. Expectancy is strictly combined with emotions. Emotions rules users decisions

Feedback should be shown in 0.1 seconds.