Yes, you DC will be interested!
You don't just trade with cast members, you trade with other pinheads too. The etiquette is to politely approach a person (guest or CM) with pins ask if they are willing to trade. If they don't tell you, ask which pins they are willing to trade. Then make an offer of pin for pin. You take your pin off of your lanyard and hold it out in your hand then the person you are trading with will place their pin in your hand and take your pin. Typically you keep your own pin back. Some private traders will wheel and deal with you but you can always refuse a trade, just politely say, "No thanks, thank you anyway." and move on. Oh, and if you see a CM with a green lanyard they only trade with kids 12 and under.
DH and I buy pin lots of 100 off eBay to use as traders (you should look for a price of about $1 or less per pin). We then load up our lanyards every day and trade. It's always fun when a kid comes up to ask if we would trade. Sometimes if I see a kid with a theme going and I have something that fits, I'll offer to trade with them. I have seen some of the biggest smiles and widest eyes when I have done that. It's a little gratuitous pixie dust for myself to see those happy faces.
Speaking of themes, that is the easiest way to not get overwhelmed and give you focus is to pick a theme. My DD is Tinkerbelle, DH likes ToyStory, me, I am the difficult one and look for character cats or corporate partner pins. But this helps us know quickly if we want to trade with someone. So, I little gentle guidance from mom and dad can help little ones zero in on what they want to trade for and not get overwhelmed at all the choices.
As far as where we look to trade, see above. We have gotten pretty good at scanning CM lanyards quickly to see if there is anything we want. Our tastes are so varied it is a total crap shoot to find what we want that we don't already have.
It does seem to help with CM lanyards to look a couple hours into a shift when they have had time to cycle their inventory and maybe have some interesting pins have been traded from guests. We just use it as an excuse to chat with people. It is a good conversation starter.
