Just consider all the choices we make because of fear - fear that we will lose our job, that we will not get a raise, that we will fail, that "the boss" will be displeased. And those are just a few of the motivators in the workplace.
Then there are the more general ones we deal with every day - fear that someone will not like or stop likening us, fear of guilt, fear of shame, fear of injury to reputation or image, fear of the loss of friendship or love.
Fear, fear, fear, fear, fear!!
And rest assured that savvy marketers know how to use fear to manipulate our choices. You might miss out on the best deal. You might not be "in" with the "in" crowd. You might suffer injury or worse. Your freedom may be in peril. Your future is in jeopardy. Be afraid. Be very afraid.
Here's another thing to consider about fear. No one likes to be afraid. That is the main reason it has such impact. On the other hand, we are unable to attach oppositional feelings to the fear itself. Instead, we most often resent or are angry at the source of the fear - the person or thing that creates it.
It might be good to consider this whenever thinking about using some aspect of fear to influence or motivate others.
The consequence of using fear as a motivator may be something to be feared.