For most companies “marketing” is all the stuff they say to people to make a sale. It’s a practice that involves running prime time TV ads, distributing glossy brochures, even flying planes over stadiums pulling banners just to get us lathered up to buy their wares. Marketing is sexy–they make those funny Super Bowl ads, everyone in their department is hot, and they really know how to use their expense account. But so often there’s a monster gap between the images they project and the dispiriting experience of being their customers. Kathy Sierra shows the disparity as something like this:

Before the Sale

After the Sale

If a company hustles me with smoke and mirrors alone, not only am I going to find out, I’m going to tell everyone I know with a giant bullhorn called the Internet. In our brave new world attention is shifting away from the pre-sales hype towards post-sales experience, because this is what people ultimately talk about. And email their friends about. And blog about. The result is that customer service is the new marketing.

But companies spend an inordinate amount of time hiding from their customers after the sale. In call centers all around the world, customer service reps are fed pre-digested scripts for every imaginable interaction (except, usually, the messy ones that actually occur). They’re automated, monitored, measured and modeled, all with the goal of constraining interactions (i.e. call times) with customers to a minimum.

Some companies have been known to institutionalize bad service precisely to deter unnecessary communication. It’s not (always) an accident we spend so much time pulling our hair out on the support lines.

Still, all this hiding from customers is expensive. So expensive that 3% of U.S. employees are engaged in customer support-related jobs. Imagine the entire population of Florida doing customer support and you’ll have an idea of the scale of the problem. And this doesn’t count the many, many more supporting us in Canada, India and around the world.

But wait, not all customer service sucks. It’s not hard to think of businesses that knock our socks off with amazing experiences from start to finish. For instance, every talented restaurant worker instinctively knows how to deliver great customer service. Then it’s magnified and rewarded by the patrons who write about them on Yelp.

Apple re-imagined tech support as a private club, i.e. the Genius Bar, and now we’re happy to wait patiently for a bit of highly qualified attention. Apple’s online discussions site extends this spirit into their customer community…as they’ve done since the old Mac User Group days, .

JetBlue and Southwest have been mastering the art of the apology. What’s so surprising is the extent to which they’re encouraging customers to talk back online in independent channels such as YouTube. Uncensored, unmoderated, out of control.

Nintendo gives its phone reps the latitude to use common sense. Last month a Nintendo customer, Saska, wrote about her broken Wii console. When she called for support, the rep discovered that Saska lived near the company’s Seattle headquarters. Without checking with her manager she invited Saska to bring the broken unit in to the office and have it fixed while she waited rather than deal with shipping it back in through official channels. She had her Wii fixed in less than an hour. Saska’s blog post about her amazing experience was Digged, influencing thousands of present and future Nintendo customers.

So here’s the big idea that we see over and over–great service turns customers into evangelists, and the Internet magnifies their enthusiasm.

Now here’s the prescription: to create great service, companies are LETTING GO of control, LETTING GO of fear of embarrassment, LETTING GO of perfection. Relaxing these things gives customers the opportunity to help companies in amazing ways, as their passions feed back into the products and services they use. It allows companies to be real instead of defensive when things go wrong. It transforms customer service from a cost to be controlled into the most meaningful, viral, cost-effective marketing imaginable.

[This is a pimped out version of my introduction to my South by Southwest Interactive panel, Customer Service is the New Marketing. Over the next several days I will post case studies based on the customer service secrets of my fellow panelists from Zappos, 30Boxes and Flickr]. Thanks to Union Square Ventures for the phrase of which this panel and post takes its name.