I've been looking into case studies of one of the world's leading digital agencies - AKQA and will be posting several campaigns of theirs from the past 2 years. Below is their unique campaign for the launch of the new Sherlock Holmes in 2009. They managed to create a truly captivating experience for their audience giving them a customized game that kept them busy for weeks with new content and improvements.
The campaign was a huge success generating coverage across different media and incredible numbers in social media mentions and views.
