Have you ever seen a billboard powered by oranges? Well neither have we, but Tropicana created one in Paris powered only off of the acidic juices in their oranges. The billboard had no connection to a power grid—only wires stuck inside the oranges connected to zinc and copper electrodes. This campaign successfully incorporates a level of shock value, but also guarantees that Tropicana lives up to its promise of providing the freshest juices to its consumers.
(page 81 in Goodvertising)