"Our Chinese clients ask for shark fin now, whereas our local clients -- and especially the younger ones -- ask for it less and less," said Peter Lai (
"Clients expect to be treated like VIPs and for Mainlanders that means shark fin soup. If they don't get it, you could lose the deal," Lai added.
The threat of 1.3 billion potential shark fin consumers is not lost on environmentalists.
"The problem is that it is being very successfully marketed in China," complained David Newberry, among the more vocal Hong Kong-based activists.
"As far as we understand, it isn't a traditional dish and -- let's face it -- it has no taste. It's just that people have been led to believe that if they don't offer it, they will lose face," Newberry said.
Activists are particularly repulsed by the method of fin harvesting, a process called "finning" in which the limb is hacked from the fish, which is then tossed back into the sea to die a painful death.
They point to studies, such as one recently by Science magazine, that suggested shark populations had halved since the 1980s, with numbers of some species, like the hammerhead shark, down almost 90 percent.
Activists scored a major victory last year when they pressured the newly opened Hong Kong Disneyland to drop the dish from its menu.
That was followed by a vow from the Hong Kong University never to serve shark fin at college functions.
Yao's conversion was another coup, but one born of a realization that the fight to ban shark fin was entering a new and more difficult phase.
"China is going to be unstoppable," Muller said. "It is newly arrived to wealth and its 1.3 billion people are going to want to share the bounty that others have had in the past."