Did you see the United Breaks Guitars video, which has now been seen by more than 5 million Youtube viewers? It's a damning expose about United's horrid handling of Dave Carroll's Taylor guitar-- and he used social media to slam back. Most successfully.
The video puts a glaring spotlight on how the quality of a company's service offerings will be transparent -- for bad and good. If a company doesn't provide the transparency, customers will.
And it also doesn't matter whether a company is participating in social media. Customers are.