This is probably old news but I just learned about it today. Facebook users in Japan can include blood type on their profiles? You can’t do that in Facebook anywhere else.
The blood type myth in Japanese culture is very much like zodiac signs. Even if there is no scientific basis, it is popular in Japan. It is the reason why you can find blood type information in magazines, manga, anime, books, websites and almost everything in Japan.
I don’t know why Facebook is not rolling this unique feature out to other countries. Don’t you think it will be useful for finding blood donors?
Below is an infographic about Japanese bloodtyping: