I went to the Stardust...
... on my first trip to a casino, the CIC chips were cool so I kept a couple. As I went to other casinos I kept a chip or two. I came back from Las Vegas with a handful of chips. I also collect currency and chips are a form of currency so I began collecting chips as well.
Today I have ~1000 chips or so. I am not interested in getting one of every chip, I pick up the ones I like. I don't collect for investment either, I am not a seasoned collector enough to. It's just pure pleasure.