A human billboar is someone who applies an advertisement on his or her person. Most commonly, this means holding or wearing a sign of some sort, but also may include wearing advertising as clothing or in extreme cases, having advertising tattooed on the body. Sign-holders are known as human directionals in the advertising industry, or colloquially as sign walkers or sign twirlers. Frequently, they will spin or dance with the promotional sign in order to attract attention.