Amongst the different actions or initiatives designed to capture people's attention in recent times, there's one that has become a real favorite with marketing departments everywhere:  the viral video.

The phenomenon is well known.  It's difficult to find anyone today who hasn't at some to been moved to tears or fits of laughter by a video on youtube that everyone suddenly seems to be talking about and sharing with their networks of friends and colleagues.  Who can forget the inspirational appearance of Scottish housewife Susan Boyle on the TV show Britain's Got Talent back in 2009?  Or maybe you're one of those who watched a particularly original dance choreography acted out on tread mills in a gym that catapulted to fame the song Here It Goes Again by OK Go.  And there are few people who by now haven't seen or at least heard of the Old Spice Man.  

Finding the formula to making your videos go viral has become a holy grail for companies everywhere.  So what is it that makes a particular video so attractive that it stirs up a storm on social networks and across the web?  Read on to find out...