A good friend of mine, who's a high-level executive at a local Internet company, had an emergency toothache. His assistant arranged an emergency operation for him at one of the best dental hospitals in Beijing, via her father's old friend who knows one of the dental experts there.
They did not have to make any appointment and just walked into the office. The old friend of the assistant's father stuffed several hundred RMB bills into the hand of the dental expert. The expert grabbed a scalpel and immediately operated on my friend.
My friend wanted to pay his assistant back for the... guan xi... money after the operation. The assistant was incensed,
"No worries about that. He's an old friend of my father's and is of the highest integrity. He'd be incensed if we pay him back."