You may have heard that acquiring a new customer can cost up to five times more than keeping the customers you already have. Yet poor customer service continues to irritate many consumers. More than half of U.S. consumers (55 percent) polled for the 2012 American Express Global Customer Service Barometer (PDF) say they’ve turned their backs on at least one potential purchase in the past year as a result of what they saw as poor service. And while only 17 percent of those surveyed say they’ve used social media to seek a resolution to their customer service query, this savvy group carries a lot of weight in how companies should respond. Why? A whopping 83 percent of consumers who use social media to try to resolve a service or support issue have bowed out of a purchase when they have a bad service. What’s more, social media users say they spend 21 percent more with companies that provide great service. And these particular users say they’re far more likely to tell others about their experience. For example, consumers who use social media for customer service will tell an average of 42 others about a good experience — and tell an average of 53 people about a bad customer-service experience. The general population, in contrast, will tell 15 people about a good experience and 24 about a negative one. Zack Urlocker, chief operating officer of Zendesk, the help-desk software behind Zappos, says the rise of social media means customers expect authentic, truthful and open communication and won’t be fooled by excuses, runarounds and insincerity. “Businesses need to develop a proactive customer-engagement strategy that seamlessly integrates social media, in order to temper the likelihood of something spinning out of control.” He said the way to do that is to make sure you talk to your customers through their preferred communication vehicle, such as Twitter or Facebook.