Carlsberg - Possibly The Best Word of Mouth in The World

Neat idea from Carlsberg in London. I love the idea of repurposed money and Carlsberg has been dropping 10 and 20 pound notes all over London with the stickers  "Carlsberg don't do litter. But if they did it would probably be the best litter in the world."

I'm not familiar with Carlsberg's campaigns in London but I can't help but wonder how to interpret  the unquestionble buzz that this campaign is driving. Does it help the brand? Could another brand be substituted easily? Thoughts? 

Thanks for my very British colleagues Ed at iStudio and Dave Fleet for the pickup.