<http://schema.org/description>
"Facebook today launched new features to help marketers reach people across devices and encourage them to take action. Custom Audiences now allows businesses to deliver targeted messages ..."^^<http://www.w3.org/2001/XMLSchema#string>
<http://thenextweb.com/facebook/2014/01/28/facebook-now-lets-advertisers-target-people-visited-site-used-mobile-app/>