A lot of people will use a sharpie marker on their golf balls to keep it separate from the other peoples' that they are playing with. And who doesn't like seeing their name engraved on anything, aside from a tombstone, and most people don't see that anyways. It's saying that that item is definitely fucking mine. There...see my name...mine..... At least that is my take on it.
edited to add- I don't think anyone wants personalized paraphernalia though... "Jeez officer, how'd you know it was mine?"