Here is a really good banner campaign case study from Uniqlo. This innovative concept and media strategy was launched for the 2009 end of year clearance. The banner campaign was in two parts, a blog / website widget and then the various banners that formed part of a competition.
The widget was embedded into blogs and websites, and when pressed, transformed every image on any website into a Uniqlo Lucky Ticket promoting the sales along with the competition.
The results were amazing! The widget was voluntarily installed on almost 5,000 blogs, generating over 2.8 million banner clicks!!