Cards for everything.
I learned that Halloween cards have been around since 1908 and that some 28 million of them are sent in this country every year. Halloween ranks seventh among top greeting card occasions (after Christmas, Valentine's Day, Mother's Day, Father's Day, Easter and graduation). It's the second-biggest home-decorating holiday, after Christmas.
Link.
It's not terribly surprising. Halloween is a $7 billion-a-year industry, making it number two (after Christmas). Easter and Thanksgiving take back seats to the ghouls. What's driving the popularity? A few years ago, I speculated that it might be sex. Link.