we just got back from a week at DLP and dd really enjoyed lots of pintrading. She was approached once by a girl with her mum, and several times cast members offered to trade with her, but mostly she approached cast members with blue lanyards in shops ad around the park.
loads of the cast members had hidden mickey cast lanyard pins and pins from the USA. She quite likes seeing ones from the shops though as I won't generally buy her the ones that cost 6 euros or more. i prefer to buy the multipacks of 5 for 18 euros or bring doubles from a big pack of traded pins from the states.
pintrading really boosts her language skills and confidence.
about half the cast members in most stores wear the blue lanyards.
there is a tiny pin store in disney studios.
there is a pin trading board that travels around the stores but it's hard to catch up with it.