My first job out of school was in retail management, and one of the first lessons I was taught had to do with angry customers, which are you're best opportunity to create an unpaid evangelist. The concept involves going above and beyond. The customer wants his money back. Give him his money plus a store credit. That sort of thing.
Seth Godin might call that a "remarkable" approach, given that the angry customer will likely be telling people (remarking) for years to come about how he was treated. And a small investment becomes really cheap, word of mouth advertising.
Gary Vee's Taylor Swift Rule is similar and a great approach for anyone wanting to prosper via social media. Check out the video below: