It all started during the Milenium celebration. Pin trading was the thing of the year 1999. Then it really kicked in and Di$ney decided to continue the tradition.
It is fun, but I think it is highway robbery too. I saw pins in 1999 that I assumed were sold out by now. Back then they sold for a little under $5. Last month we saw several of the exact same pins, made over 3 years ago, selling for almost $9!
So cast members, when they feel like it, wear lanyards and trade pins with guests... Some collectors turned very compulsive and outrageous, so some CMs now only trade with children or just choose not to wear lanyards.