This aids the hunter in building up hate towards a specific target. This is useful if you are partnered with a priest, or any other non tanking class. This is also useful for pulling off of your pet, if their life starts to dwindle.

I've used it a good deal in pve play and it works like others have explained. What I have not done is to use it in pvp or even when a pve is actually running from me... I've heard that it will actually break the focus of the pve and/or pvp, stopping them and turning them to face you. Has anyone else actually tried using it when a person was in the act of running away.