Dutch airline KLM has 150 social media agents running conversations from Twitter to Facebook and WeChat, and it is not only customer service they provide. The airline fields 70,000 queries a week, and some of them are turned into bookings as the agents can, directly from social conversations, provide flight details and links to booking pages. Every agent represents approx. 170,000 USD in annual revenue. Social is becoming a profit center, besides being a customer service tool.
From the email sent to me after my last booking with KLM: