The words we say can make an impact either positive or negative. Even if we think a little gossip won't do anything, we don't know what might happen. It could effect people's relationships, or job and so forth. It's like this metephore of a pillow with feathers and the feathers fly away, we can't bring it back. So too, we can't bring the words back once the damage is done. Besides regular gossip, we also need to be careful not use our words as weapon to emotionally hurt others, but instead use our words to positively build people up. If we are careful with this, we can keep relationships strong, and bring blessing to ourselves and all around.
Of course, there are times when one might need to say something, but then you should talk to someone who can take care of it.