I'm not in any means a hardcore pin trader or collector, but I admit that seeing those shiny walls of pins gets me excited every time. For me, finding pins of some of my favorite characters, lands, or attractions, is why I buy them. It's like taking home a tiny memory from your trip. I'm not sure what it is about them that I like so much except that their cute, show off my favorite characters, and I can wear them proudly on my lanyards.
I've noticed recently that when I wear my two lanyards covered in pins, everyone stares at them. People I pass, people next across from me in line, they all seem to be entranced by it.
"Well I don't know about you folks, but it's way past my bedtime."
If you really want to get into it just pick one style to collect and you just may get addicted...As for me I collect anything Disneyland park related and I even special it down even further to just the haunted mansion. I probably have over 300 HM pins. I just like collecting them and trading them. you meet some interesting people as well and can engage the CMs if they have them on.