<http://schema.org/description>
"For the past several years, we've seen advertisements on billboards increasingly integrated with audio and video elements as if creative agencies were playing catchup with the broadcast ..."^^<http://www.w3.org/2001/XMLSchema#string>
<http://thenextweb.com/apps/2011/04/19/immersive-the-future-of-display-advertising-is-here/>