A YouTube film campaign used Annotation Technology to enable viewers to choose what happened next. Carry a knife? Go to a party? Stab an opponent?

After experiencing the consequences of their choices, viewers could ‘Choose a Different Ending’.

21 films, ten different endings.Seeded online, the campaign appeared unbranded, employing social media, search, in-game posters and blogs.

Results and Effectiveness •4.6 out of 5 average user rating.•2.1% click-through rate on viral video trailers, well above 0.2% industry benchmark for rich media banners.•Net number of views logged would have required a TV budget 600% the size of our spend.•Peer-to-peer debate about the videos and knife crime swelled. At peak, more than 80 comments a day were posted, with a total of over 3,000.•Total views to date, 2,652,012.

•Highest total recall of any Metropolitan Police campaign, ever. 78% among our target.