<http://schema.org/thumbnailUrl>
<http://cdn1.tnwcdn.com/wp-content/blogs.dir/1/files/2011/12/Groupon-520x245.jpg>
<http://thenextweb.com/insider/2013/07/01/groupon-reserve-is-a-premium-restaurant-booking-service-for-discounts-without-pre-payment-or-vouchers/reserve/>