Their name in Korean means Yakult women: street peddlers who sell several probiotic drinks, including Yakult. I encountered them in a Seoul suburb (Bundang) on the way to the subway. During one 15-minute walk, I saw three of them. Other street peddlers in Bundang were often men (selling cookware or socks, for example) but the probiotic sellers were always women. I haven’t seen street peddlers selling probiotic drinks anywhere else. In Japan, Yakult and other probiotic drinks are sold door-to-door but apparently not on the street.
I asked a Korean friend how she (and Koreans in general) got the idea that probiotic drinks are good for health (which I am sure is true). She said she knew it before she went to school and believed she picked it up from TV ads. Apparently these ads are more successful in Korea than elsewhere. General Foods recently paid $9 million to settle a legal case based on Yoplait Yo-Plus ads in America that made similar claims. The lawyers who sued General Foods claimed that healthy people don’t benefit from Yoplait Yo-Plus.
I can think of several reasons that Yakult women exist in Korea but (apparently) nowhere else. Maybe the fact that Koreans eat a lot of kimchi makes them more likely to believe that a probiotic is healthy. Maybe Koreans care more about health than other people. Maybe Koreans are unusually sophisticated about health. Bundang’s density (it is full of tall apartment buildings) is surely one reason, because Yakult women weren’t the only street peddlers. American suburbs, where I almost never see street peddlers, are much less dense. Another certain reason is that Bundang is a wealthy suburb. A third certain reason is that Yakult and similar drinks help you digest lactose. Lactose intolerance is much more common in Asia than elsewhere.
It would be interesting to compare the rate of digestive problems in South Korea versus other countries, especially the United States. I think they are likely to be much less common in South Korea.