Green graffiti

Guerilla marketing with a difference: Ads that take advantage of our dirty streets.

Much like "dirty car art", Dutch-based Green graffiti tackles pavements and walls: "With the help of a template and a high pressure water sprayer an advertising message is cleaned out of the dirt. "

Not only is it cheap as you don't actually buy any space, no environmentally unfriendly inks are used. Depending on the execution, it can also be more eye-catching than your standard poster ad.

Finally, while fly-posting and wall markings / chalkings can theoretically get brands into hot water, you'd imagine any over zealous local official would have less of a leg to stand on here given it's nothing more than a water mark in the urban grime (and so as much of a social statement as an ad).

Depending how tardy your local council is in keeping the streets clean, Green Graffiti's creations apparently last for up to six months.

Pictured: Before and after shots for Dutch brand 5010, and Smart car advertising.