Human billboards 

People who collect in standouts at rotaries or on overpasses with campaign signs. Sometimes to advertise a menu, or just a sale.

(i guess it is a New England thing)

Look at that human billboard

Human billboards by wickedNH February 6, 2004

human billboard

A person who wears garments decorated with corporate logos, or slogans. The logo can be either the manufacturer or designer of the garment, or a sponsor (eg sports event sponsor). On a deeper level it refers to someone who feels that they must advertise their income level or taste in clothes in an obvious way to gain peer approval. Also refers to someone who unwittingly engages in the act of advertising by wearing such garments.

Wearing tracksuits or baseball caps with company logos, bags with the name of the designer printed on them. 'The human billboards thronged around the pit area like dancing biped TV ads.'

human billboard by Tim Francis May 25, 2007