You can't give the customer what he asks for, but you can still make sure he leaves happy.
Last week I proposed that the customer may not always be right. (No, really.)
So you're faced with a customer who wants you to stick a flag up your nose and whistle the Star Spangled Banner. Or, more likely, a customer wants tickets to Saturday's football game, which has been sold out for months. Not only is he furious, but he takes it out on you.
It may seem like there is no way to make him happy, but it isn't true. There's no way to get him tickets to the game, but that doesn't mean he has to leave upset and distraught.
Step One: Empathize. Justify their anger for them. A customer is mad because the iPod she bought second-hand isn't working. You can't replace it, because it's out of warranty, but she was duped by an eleven-year-old kid who lives two doors down. Say this: "He told you it was brand-new, but it's actually over a year old. What a punk. I'd be mad, too." A lot of energy will be dissipated once they realize you understand them. (Even if you secretly think anyone who buys second-hand iPods from school-children is idiotic.)
Step Two: Distract. Change the topic, but only slightly. To the man who wants tickets: "I hear Kraveki's still on the injured list." You know he likes football, so let him rant and rave about what a crap team it is this year and how the coach knows nothing about coaching.
Step Three: Flatter. "Sounds like you could tell that coach a thing or two." Or, to the iPod woman: "Awesome playlist. I love The White Stripes."
Step Four: Don't tell them what you can't do. Tell them what you can do. "I can sell you tickets for the game against OSU." "I can replace the whole unit for $70." "I can't whistle the Star Spangled Banner, but I'd be happy to hum it for you."
You get the idea. These steps, performed in any order, will help calm down even the most irrational customer. Unless he's the Unibomber. Then you're on your own.