Answer:
Goliath, The Jolly Green and Andre are all examples of this.
The day is their night and the night is their day, when I shout and they shout back I run away.
Lots of them make up a word, And lots of words are in them. It's easy when you think about it. A while ago we stamped and mailed them.
What do people spend a lot of money on every year but never want to use it?
What falls down but is never injured?
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?