Yowl of the Bloodmoon  

I don't know what world you live in where this is not by far and away one of the strongest tools that you have. Regardless of how much damage the charmed mob does (and it's really not that small of an amount, usually ~60% my dmg at 80 in full raid gear) the whole point is that the charmed mob is being beaten down for free, and then you can use fade to drop charm whenever you want and get the credit for the kill.

The duration is short, but with full AAs and Rk II. or Rk III. it will actually last over a minute long. (although it will rarely actually last full duration) I have a macro set-up that switches to a bandolier with Epic 2.0/Wind Instrument and casts charm, then make pet attack your second pull and then they just beat each other up and you get all the benefits. I personally run with a Cleric box so I am able to just recast charm when it drops and not worry about it, because it will, and sometimes frequently. Regardless though, if you are persistent, and have decent gear and AAs then this is always a viable exp strat. If you are entirely solo then you just pull a group of 5-10 mobs and dirge dump then kill them all with single target dots while kiting, and while you do that you can use charm and add more free damage. This all just takes a lot of micromanaging, knowledge, comfortability, and skill.

Charm is so strong that in many groups when we don't have a tank I am just setting up pulls with charm and we kill. Please do not sleep on this one as a Bard.