<http://schema.org/description>
"Whatever side of the website advertising world that you're on, whether you're buying or selling, you're likely familiar with the work that goes into getting advertising onto a page. ..."^^<http://www.w3.org/2001/XMLSchema#string>
<http://thenextweb.com/apps/2011/04/20/isocket-a-better-smarter-way-to-buy-and-sell-website-ads/>