<http://schema.org/thumbnailUrl>
<http://cdn1.tnwcdn.com/wp-content/blogs.dir/1/files/2012/12/Pinterest-Main-Images-520x245.jpeg>
<http://thenextweb.com/socialmedia/2012/12/29/how-to-increase-pinterest-traffic-direct-it-to-your-site/6/>