Halloween is big business in the USA. Many weeks before the actual event, the shops are full of skeletons, pumpkins, witches, cobwebs and ghosts. Apparently it's the second largest holiday in terms of dollars spent; second only to Christmas.
It's a little disquieting how seriously it's taken over here. The restaurants start putting pumpkin in everything, little kids solicit sweets from unlucky neighbours, and people really enjoy dressing up.
I went to the Halloween parade in Greenwich Village three years ago and was stunned by the scale of the event, and the amount of effort some people put into their costumes. Apart from the one lady I saw whose "costume" consisted of no costume at all. Yep, she was in the middle of the parade with nary a stitch on. That's a different kind of freak show altogether.