Chinese laws tolerate titillation, but outright sex? That'll incur the wrath of the authorities.

A friend of mine who partners one of the big platforms told me that a hostess can actually make much more money if she is willing to "meet up" with those who bought her virtual rockets or flowers. It has nothing to do with the website, he says, which nominally forbids sex for money.

Admittedly, the websites have employees policing the chat rooms. But how can a staff of a dozen be effective in monitoring all the monkey business going on in hundreds of thousands of rooms?

So they use filter words such as "sex", which spawns countless euphemisms. Their software is able to catch suspicious behavior through the analysis of graphics, they claim. And the red light goes on whenever there's a sudden spike in viewership to one room.

All this reminds me of the dichotomy in China's magazine market. Metropolitan residents would never know this until they go to a bus station in a county-level city where magazine stalls have none of the glossy titles ubiquitous in big cities. Instead most titles are priced below 3 yuan and feature such headlines as "Woman's headless body found floating in local river".

Chat rooms are said to cater to that demographic, which is huge but below the radar.

If belated regulation of other online activities is any guide, there will be a crackdown down the road, and chat room hosts may have to be vetted by government entities rather than agents who pressure them to "accidentally" drop whatever scanty thing they are wearing.