If you feel that your only option is to gamble on creating content that might go viral, it’s worth knowing the characteristics known to make it more likely. An analysis I conducted during my time at research company Kantar Millward Brown (2011) identified the characteristics of video ads that achieved high levels of exposure due to social sharing. These videos tended to score exceptionally highly in at least one of these four areas, often in several of them. These are what give videos the 'legs’ to go viral.

Check out this LinkedIn thread for a discussion about the topic.