Originally Posted by visceral

From a tourist blog. Hope it helps:

This is a warning to those visiting China, especially the big cities.
Whilst site-seeing in Shanghai, we were approached by 3 friendly young Chinese 'students' who said they were also visiting Shanghai from Xi'an.
They asked us questions about our home country, (England) and we chatted for a while. They then said they were planning to visit a tea house to find out about traditional Chinese tea/ tea ceremony and would we join them as they wanted to practice their English. Against our better judgement we decided to go with them. To cut a long story short, our politeness cost us over 200 RMB for two thimble sized cups of tea. We felt so stupid, but somehow fell for it as they appeared to pay up for their tea too. What was happening was that they were getting paid commission by the tea house for conning unsuspecting tourists inside. We saw other tourists being led into these places by groups of young Chinese people.
If visiting China's cities, be wary of these groups trying to befriend you. They use many different techniques.