Beattie McGuinness Bungay (BMB) is the creative agency behind a brilliantly clever new interactive campaign for Grolsch.

BMB was commissioned by the beer-maker to design an interactive experience that would communicate to the audience that Grolsch is a "rare character" among lagers. The campaign needed to better its predecessor, the interactive 'Big Bold Grolsch' campaign BMB created in 2012. And so, the 'Rare Character Test' was born.

Visitors to Grolsch's website are invited to try the 'Rare Character Test' to be in with the chance of winning one of 5,000 4-packs of the beer. The test involves sending an answer via text message to the number shown on screen. That answer will then appear within the interactive video, after which Grolsch's character will proceed to call you to let you know whether your answer determines you to be a rare character. If you are, you've won yourself some beer!

There are a total of four questions and approximately 40 separate responses to cover all eventualities within the campaign.

The campaign's art director Olly Wood and producer Melanie Lowings told us: "The main technical challenges came from the fact that we were delivering something that hadn't been done before so there was a lot of trial and error."

BMB used the Twilio call platform, but the difficult part was that it was being used in a completely new way as part of a seamless, interactive, personalised user experience.

"We also had to work around potential video/call syncing issues, caused by external factors such as the user's broadband speed or mobile network coverage," said Mel. "We used a series of cut away or obscured images to maintain the illusion of a real time telephone call with our psychoanalyst."

"This project taught us that we have the opportunity to make things that aren't considered possible, possible," Olly added. "Have the idea, then find out how you can make that idea happen."

If you haven't tried it already, we urge you to give it a go. It's great fun and a fantastic piece of interactive online marketing. To try it for yourself, click here.