5. Pickpocketing takes almost no time whatsoever to do. - Ever find yourself staring at a mob's back while the tank is establishing threat/aggro? Hit your pickpocket button. The mob isn't even going to notice you rifling through its pockets when someone is beating the snot out of it. You'd be surprised how many bosses actually have pockets -- and perhaps even more surprised at what's in those pockets sometimes. The worst thing you'll get is a "no" in text, which leaves you no worse off than you were before. While you're out farming for something, hit the pickpocket button before you nail them with your opening move. If you're worried about them detecting you and having to vanish, try facing away from the mob in question as opposed to facing towards them, or try doing it from max range just before you step in to land your opener. Both seem to help from my experience.
4. You can find some really fun stuff while pickpocketing. - I've picked up a lot of strange and interesting stuff, myself. My favorites include [A Frayed Knot], [A Gnome Effigy], and [An Exotic Cookbook]. At the worst, you can send them to guild mates, or sell them to vendors. Best case scenario, you can sell certain things on the AH. For example: I know I make a killing every Valentine's Day selling the [Red Rose]s I get pickpocketing. There are generally lots of people more than willing to spend 1g on something sweet for their WoW Valentines. Also, once in a great while you'll even get something like [An Antique Gun] (which apparently the Firefly fans dig) that will sell for crazy cash. Case in point: that particular gray item sells for over 3g to a vendor.
3. Save yourself from wasting time in game hunting down static chests and doors to skill on. - Pickpocketing gives you the chance to access lock boxes of all different levels. Getting lots of those can save you from having to waste your game time grinding your lock picking skill in places like Tanaris or Stonetalon Mountains. Besides, think of how embarrassing it would be to stand in front an instance door and have to ask someone in your group to let you in because you can't pick the lock. Or worse still - how about when you're running with a group and you can't open the locked chests in the instance because your skill isn't high enough. You deny yourself and your group whatever sweet sweet goodies are inside. I know I'd hate to be that Rogue!
2. Pickpocketing will save you money if you make use of it. - Remember those lock boxes I just talked about? Well, aside from being good for skilling up your lock picking skill, they generally contain some coin, and usually either reagents like [Flash Powder] or poison ingredients like [Maiden's Anguish]. I've personally picked up an enormous amount of Super Healing Potions since I hit Outland just from pickpocketing, but you can get lots of healing potions at all levels if you just make use of your skill every chance you get. Hooray for not having to spend money on potions at the AH, or materials if you're an Alchemist. And keeping more money in your pocket leads us to my next point...
1. Who doesn't like free money?! - Come on, can any of you honestly say you don't like extra gold? Pickpocketing can net you quite a lot of coin -- and that's on top of your share of whatever the mob drops normally. Now I'm not saying you should run through an area and pickpocket everything in sight without killing those mobs. (That's just a professional courtesy to your fellow WoW Rogues. You wouldn't want to be the one who had that happen, either.) And contrary to some popular misconceptions, pickpocketing is on its own separate loot table. So you aren't taking anything away from the group's loot when you pickpocket mobs. You're just enjoying the extra little bonus cash that all Rogues were designed to get. And really, when it comes down to it, it fits our idiom!
This ends my Top 5 reasons on why you should be pilfering through pockets for cash and prizes. Sure, there are other reasons, but these really strike me as being most important based on my experience with the Rogue class. Hopefully the Rogues out there who haven't been pickpocketing will take this to heart and help themselves to the spoils of war -- and pockets!