from this site i saw...
"I travel all over China, and often see interesting things. Of course, some of these things are part normal everyday life in China's eastern culture, but might be very different from what you'll see in western cultures.
If you want to buy a goldfish or baby koi fish in Nanjing, this is where you will end up.
Of course, in China, you can buy a lot of things from the back of big tricycles. Everything from fruits and vegetables to cakes, candy, and even heating coal.
These tricycles are actually totally mobile stores, and can be found on different street corners every day.
I think it's brilliant, because once you've sold your goods to everyone in a neighborhood, you simply pedal your tricycle a few blocks away, and see how sales go there.
Of course, many of these entrepreneurs are not actually licensed businesses in China. So when the police come by, the tricycle retailer becomes a tricycle transporter, and zips down the street looking for police-free area.
In Nanjing, all of these tricycle-goldfish-retailers seem to where the same uniform, of a black leather jacket, black slacks and running shoes.
Proof of this can be seen in these two pictures. These are two completely different goldfish sellers, but they are both donning the same outfit.
One of the sellers told me that he offers a "one-week-no-die" guarantee. It seems like a good policy to me, except for the fact that in a week, you'd have to search pretty hard to find next week's street corner location.