Throughout the weekend that the Red Balloon activity was live, a film crew documented the event and produced a two-minute film, which was shared on youtube.com.

We actively decided not to invest heavily into promoting the film online as it was considered powerful enough to achieve good results on its own merit. The work was a social experiment to see how far the happiness we generated would spread by itself. The film wasn’t even shared on Coca-Cola’s Facebook page

Simply put, we had to have faith in the spirit of the brief and the answer we came up with. No stunts. No search engine trickery. We would only be true to our own message if we trusted in the emotional power of the idea itself as its own engine for infectious sharing.

As such, the campaign had global potential online, for all age-groups in all nations, with no restrictions or regulatory concerns.

Coca-Cola has been encouraging us to share happiness for years, so who better to inspire random acts of kindness that would spread the joy of Christmas just that little bit further?

However, a random act of kindness isn’t really that if you tell people to do it. They need a playful nudge, a simple choice to be kind or not.

Our digital installation was just that, a social experiment to test whether people are happier giving rather than receiving.

It allowed us to flip expectation on its head, creating drama and astonishment among thousands of people, and infectious online sharing.

With a budget of only £50,000, we had to trust our proposition. Could we create so much delight that happiness itself could be its own engine for sharing?

In 48 hours, over 1,300 people interacted with the machine. 80% actively chose to give rather than receive, sharing over 1,000 random acts of kindness.

The experiment was posted on YouTube, surpassing every expectation, generating conversations on blogs and social media in over 50 countries. Over 800,000 people actively engaged with the activity. Coca-Cola said it was "the best content delivered across (the) CSE market (in) 2013".