Last night, I played my level 33ish mage for the first time in ages. My hunter did the 30-40's in Stranglethorn Vale, my 34ish priest has just headed to Desolace to quest there, and so I took my mage to Tarren Mill with the intention of running to the Arathi Highlands to quest there. May as well mix things up a bit so I don't get bored leveling two toons in the same area.
Anyway, when I got to Tarren Mill, there were several Alterac quests available, so I picked them up and started wandering around. May as well take care of a few things here, too, I thought. To make a long story short, I wandered into a zone loaded mobs a few levels above me and completely got my butt kicked. It was kind of embarrassing. I was killing the green stuff just fine (and naturally, the grays), but an yellow mobs were totally destroying me. Not even elites -- just plain yellows! My priest certainly hasn't been having trouble with the yellows, so ... what the heck?
I got smushed several times before I realized I needed to take a step back and really look at what I was casting. This is where Violation, the damage meter I installed came in really handy. I found some green mobs and started playing with my spell rotation until my DPS was looking better. I also spent some time reviewing how much mana each of the spells required. I'd mentally assigned values to them (evidently based on my very poor memory) that were way off. Good to know.
So, with increased DPS and a better idea of how to conserve mana, I proceeded to the Arathi Highlands. (I might go back to Alterac some day, but I must give the mobs some time to forget, lest the coach call the outfielders in... easy out, easy out...) I found the cave with the Ogres I was supposed to kill, and made my way inside. I actually did quite well in killing them. I did have to stop and eat leftover Halloween candy a few times, and I died once after some ill-timed respawnings, but I successfully completed the quest and ran to Hammerfall, feeling very proud of myself. And boy, were the greens easy after that...
So, clearly, using damage meters as a diagnostic can quickly improve one's game play. There are stories stories all over the place, however, about folks using damage meters instead to try to outdo each other's DPS in a group, sometimes to the detriment of the party, pulling aggro from the tank and so forth. I do agree with BRK's sentiment that "Wow is NOT a DPS race," but I can see how people fall into this...
The game keeps you hooked by offering you goals, some big, some small. The game even tricks you into completing bigger tasks (like grinding for experience) by offering you seemingly small tasks: "Collect 10 naga eyeballs." 10, you say, rubbing your bleary eyes. I can do that and still be in bed at a reasonable time tonight. And then the drop rate isn't as high as you hoped, and you've killed 100 nagas (90% of which are blind, apparently), and you're up for an hour longer than intended... Anyway, my point is that having a damage meter there offers another small goal that you can probably achieve during the course of an instance if you're a DPS build.
I won't lie, either -- it's fun to be at the top of that DPS list. Before I go into an instance now, I reset Violation so I can check it periodically and see how I'm doing. My goal isn't to be at the top, however. I tweak my casting rotation in response to the threatmeter, not the damage meter.
I also don't make a big deal out of it should I find myself at the top of the list. I've been in instances where the players beg someone to post the damage meter stats, presumeably because they know they'll be at the top. When I ran Scarlet Monastery with my hunter a while ago, a paladin, who was the sole healer, even requested that the healing stats be shared, too. "Why? You're the healer, so of course you'll be at the top," someone pointed out. "I just want to see it," they said. Somehow it makes people feel like they're winning the game, I guess. Again, the wisdom of the man they call BRK: "...topping the damage-meter is not The Goal; defeating the instance is." Well said.