Here is a great example of a simple yet powerful way to engage audiences into your concept. Freedom is a Dr. Martens campaign to give right back to their target audience who happened to be an eclectic group of individuals and subcultures, and thousands of rock bands who wear their boots. They did so by giving new bands the chance to play in London, Manchester, New York, California and Ibiza, supporting bands like The Arctic Monkeys, Kasabian, and Dirty Pretty Things; supported spoken word projects in San Francisco; and exhibited artists in New York and Tokyo; created a performance studio at the Roundhouse in Camden, London. The list goes on.
To celebrate this, they pumped out this sweet little site that allows people to express themselves on a blank boot right there on the site, and share. Pay attention to how it involves the audience to vote and is integrated to the social medias out there. They close the loop quite well, but more amazing are the designs that are being done.