Generally, it gives people a mixed feeling of satisfaction & guilt at the same time. even though it gives satisfaction thinking about the deep, deeo down you feel like you ended up lowering or standards to those who hurted you in the first place. as time passes there could be possibilities of regrets or shame associated with the nature of the deed. although revenge if taken in terms of justice could be satisfying at times. Say a person is laughed & insulted everyday by his associates he stands up for himself one day to get rid of his miserable condition then that would be quite satisfying for the person even if his/her associates judges the action as an act of revenge.