"That would be a lot of good business, wouldn't it?" asked Ezra Gottheil, an analyst with the Technology Business Group. "Is it a matter of they've got to do it or be in trouble? No. But could this be very important for them? Oh, yes. The market there is enormous. It's astronomical."

Gottheil added that Baidu's Li might offer Zuckerberg a bit more than lunch and friendly advice.

Where China has concerns about Facebook and opening up its Great Firewall to the social network, government officials might be more willing to work with Facebook if there's some sort of supervision. And that's where Baidu might come in.

"If this is going to work, it's going to take people," said Gottheil. "If China is concerned about Facebook, they'll want some kind of oversight and then it becomes very people intensive. It might very well be that [Zuckerberg and Li] are talking about a licensing deal or a revenue-sharing arrangement."

Gottheil also noted that China might insist on Facebook's only working behind the Great Firewall for its own citizens.