This is my idea: I would like to start an English Stamps Club here in Japan. Young people (and old) may join. I would send them these stamps. They are quite common, so I have enough of them for 49 people to join the club. By using English to follow a hobby, their English would improve.
I haven't started the club yet. If enough people are interested, I'll go ahead. So let me know if you think it's a good idea.