Air Pollution Guerrilla Marketing in Chicago

"The shape and text was created by power-washing filthy sidewalks using a large stencil form. [..] Sidewalks are usually very filthy and just the thought you could make your point by creating a clean spot instead of a dirty one is one to cherish. This is a form of non-destructive guerrilla marketing in it’s purest form." What a good idea! Any readers from Chicago saw them? Via ::Coolz0r, ::Ads of the World. See also ::Atmospheric Pollution Ads from Singapore