Outdoor billboard advertising is nothing new, today's top marketers are innovating they way they use experiential marketing to tell their brand stories.

The web-based exchange connects advertisers with billboard owners without the need for document swaps and epic location-scouting.

From viral campaigns to virus campaigns, we pick the 10 marketing initiatives in 2011 that hit on that winning combination of great idea, perfect timing and flawless execution.

The founder of an outdoor-ad marketplace on innovation and entrepreneurship.