When I read this I thought "What a great idea for a topic!" so I created one.Adding a 'kicker' to a working effect diminishes the effect. Adding one or more 'kickers' to a poorly presented effect is just about like kicking a dead horse. Maybe that's why they are called 'kickers'. In general,why bother?
While I generally hate making allusions to attacking an audience ("I killed 'em" or "This will knock them off their feet") I think this is an appropriate time.
"The Greatest" revolutionized boxing by using a kicker philosophy. He realized that it's very difficult to hit someone so hard that it knocks them out but that if you hit them less hard, but many many times, so quickly they can't process each impact, that it will have the same ultimate effect.
Isn't that what "kicker" endings attempt to do? Overwhelm the senses and overload the critial thinking processes of the audience so that they simply give up trying to determine what you did and accept the effect?
I find that sometimes a kicker can serve tell the audience that he effect is over. Many tricks in magic simply repeat the same effect over and over again. A kicker, if it's thematically valid, can serve as a nice coda.
But that's just my opinion. I could be wrong. :D